Gulf of Alaska 1300 Year Temperature Reconstruction ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Gulf of Alaska 1300 Year Temperature Reconstruction LAST UPDATE: 12/2009 (Original receipt by WDC Paleo) CONTRIBUTORS: Rob Wilson, Greg Wiles, Rosanne D'Arrigo, Chris Zweck IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2009-149 WDC PALEO CONTRIBUTION SERIES CITATION: Wilson, R., et al. 2009. Gulf of Alaska 1300 Year Temperature Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2009-149. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Wilson, R., G. Wiles, R. D’Arrigo, and C. Zweck. 2007. Cycles and shifts: 1,300 years of multi-decadal temperature variability in the Gulf of Alaska. Climate Dynamics, Vol. 28, pp. 425-440. DOI 10.1007/s00382-006-0194-9 ABSTRACT: The Gulf of Alaska (GOA) is highly sensitive to shifts in North Pacific climate variability. Here we present an extended tree-ring record of January–September GOA coastal surface air temperatures using tree-ring width data from coniferous trees growing in the mountain ranges along the GOA. The reconstruction (1514–1999), based on living trees, explains 44% of the temperature variance, although, as the number of chronologies decreases back in time, this value decreases to, and remains around ~30% before 1840. Verification of the calibrated models is, however, robust. Utilizing sub-fossil wood, we extend the GOA reconstruction back to the early eighth century. The GOA reconstruction correlates significantly (95% CL) with both the Pacific Decadal Oscillation Index (0.53) and North Pacific Index (–0.42) and therefore likely yields important information on past climate variability in the North Pacific region. Intervention analysis on the GOA reconstruction identifies the known twentieth century climate shifts around the 1940s and 1970s, although the mid-1920s shift is only weakly expressed. In the context of the full 1,300 years record, the well studied 1976 shift is not unique. Multi-taper method spectral analysis shows that the spectral properties of the living and sub-fossil data are similar, with both records showing significant (95% CL) spectral peaks at ~9–11, 13–14 and 18–19 years. Singular spectrum analysis identifies (in order of importance) significant oscillatory modes at 18.7, 50.4, 38.0, 91.8, 24.4, 15.3 and 14.1 years. The amplitude of these modes varies through time. It has been suggested (Minobe in Geophys Res Lett 26:855–858, 1999) that the regime shifts during the twentieth century can be explained by the interaction between pentadecadal (50.4 years) and bidecadal (18.7 years) oscillatory modes. Removal of these two modes of variance from our GOA time series does indeed remove the twentieth century shifts, but many are still identified prior to the twentieth century. Our analysis suggests that climate variability of the GOA is very complex, and that much more work is required to understand the underlying oscillatory behavior that is observed in instrumental and proxy records from the North Pacific region. GEOGRAPHIC REGION: Northeast Pacific PERIOD OF RECORD: 724 - 1999 AD FUNDING SOURCES: US National Science Foundation Grants ATM02–02898 and OCE 04–02474. DESCRIPTION: Tree-ring based reconstruction of January-September Gulf of Alaska coastal surface air temperatures. This regional series is based on STD standardization of a composite treering data collection of living and subfossil samples. The STD chronology file is archived in the ITRDB at: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/chronologies/northamerica/usa/ak096.crn The composite tree ring measurements file from which the chronology was computed consists of 820 living and subfossil tree ring data series. The measurements are archived in the ITRDB at: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/measurements/northamerica/usa/ak096.rwl This composite collection is more fully described at: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/measurements/correlation-stats/ak096.txt DATA: STD Gulf of Alaska Regional Temperature Reconstruction January-September temperature in degrees Celsius YearAD GOA Temperature Reconstruction 724 4.4378 725 6.1228 726 6.1828 727 6.1565 728 5.5411 729 4.8281 730 5.5974 731 5.8563 732 5.5636 733 5.436 734 5.4022 735 4.9069 736 4.8168 737 3.6497 738 3.8598 739 4.0137 740 4.5203 741 5.6049 742 5.2859 743 6.3742 744 5.9426 745 5.1696 746 5.2784 747 4.5691 748 3.8336 749 5.2371 750 6.1603 751 6.697 752 7.4513 753 6.5356 754 4.1225 755 4.3027 756 4.2576 757 3.7773 758 4.5691 759 4.8656 760 5.0532 761 5.5636 762 6.3404 763 6.4755 764 5.9652 765 6.0777 766 5.361 767 5.102 768 5.1846 769 4.6141 770 4.3327 771 4.6817 772 5.6537 773 5.2521 774 6.5581 775 7.2336 776 7.2073 777 6.6407 778 6.0815 779 5.9014 780 5.132 781 5.102 782 4.6592 783 4.1338 784 4.2876 785 4.6667 786 6.1828 787 5.5561 788 6.4343 789 6.1115 790 6.3667 791 6.9034 792 7.106 793 5.6274 794 5.5598 795 4.9707 796 5.1696 797 5.3309 798 5.5636 799 5.9239 800 6.4718 801 5.8976 802 5.5336 803 4.9857 804 5.2896 805 5.4323 806 5.9201 807 6.3667 808 7.4963 809 6.7007 810 6.1228 811 7.0197 812 5.5148 813 6.5844 814 5.5448 815 5.8563 816 5.2896 817 6.029 818 6.0027 819 6.9184 820 6.1565 821 6.119 822 8.0555 823 6.0102 824 4.9632 825 5.1883 826 5.2409 827 4.3102 828 4.8281 829 5.4398 830 5.102 831 6.2841 832 6.6181 833 7.9279 834 6.9409 835 4.9294 836 4.7605 837 4.9669 838 4.434 839 4.5691 840 5.1621 841 6.1003 842 6.7795 843 6.4493 844 6.483 845 5.2934 846 6.074 847 5.8939 848 6.727 849 5.1358 850 5.8376 851 4.3214 852 4.7492 853 3.9987 854 4.5541 855 5.1733 856 4.1938 857 6.1791 858 6.1565 859 6.3479 860 5.9877 861 5.9539 862 5.481 863 4.783 864 3.9912 865 4.2501 866 4.1413 867 4.3102 868 5.0607 869 4.8581 870 5.421 871 5.7175 872 6.1453 873 6.5881 874 6.438 875 5.9389 876 6.4005 877 5.7925 878 5.7625 879 5.0269 880 5.7663 881 6.5056 882 7.0985 883 6.483 884 5.6349 885 6.2879 886 6.2616 887 4.6479 888 4.1638 889 4.7005 890 4.6629 891 5.4022 892 6.4905 893 6.8396 894 7.3462 895 7.2261 896 5.5598 897 4.5691 898 4.7417 899 4.9556 900 4.8994 901 5.0007 902 5.0457 903 4.5916 904 5.0082 905 5.0757 906 4.6892 907 5.481 908 4.9819 909 4.5916 910 5.1395 911 5.7362 912 5.3422 913 5.436 914 6.1678 915 6.1453 916 5.3534 917 5.8263 918 6.0402 919 5.8338 920 5.0645 921 4.4152 922 4.2952 923 4.9969 924 5.3047 925 5.3347 926 5.3985 927 5.7475 928 5.3534 929 6.4267 930 6.1678 931 5.8188 932 6.2128 933 5.9802 934 5.0757 935 5.7625 936 6.0177 937 6.2654 938 6.029 939 5.6274 940 4.2276 941 5.0382 942 5.2671 943 6.4042 944 7.0985 945 6.6557 946 6.4643 947 5.9501 948 6.7983 949 6.9859 950 5.9276 951 4.8656 952 4.3815 953 4.3965 954 5.2521 955 6.4493 956 7.3987 957 7.6764 958 6.0815 959 6.0852 960 6.378 961 6.6632 962 7.3875 963 6.8058 964 7.4288 965 7.5376 966 7.5413 967 7.8791 968 7.2336 969 4.1488 970 3.0192 971 3.3832 972 4.2764 973 4.7755 974 6.2541 975 5.3459 976 5.1771 977 6.1528 978 5.5786 979 6.1228 980 5.4885 981 5.0044 982 4.3439 983 4.8468 984 4.8693 985 5.2446 986 6.4117 987 5.5749 988 6.1265 989 5.3947 990 5.0907 991 4.7005 992 4.9632 993 5.5674 994 5.4172 995 5.8301 996 5.8863 997 6.2316 998 6.1603 999 6.0027 1000 5.0532 1001 4.4715 1002 5.0457 1003 6.2391 1004 6.5656 1005 6.074 1006 6.8058 1007 6.6106 1008 6.5356 1009 6.044 1010 3.8636 1011 4.0662 1012 4.2689 1013 4.4227 1014 5.0157 1015 5.481 1016 5.9239 1017 6.119 1018 6.9409 1019 5.1996 1020 4.8881 1021 4.5879 1022 4.9969 1023 5.8676 1024 4.2689 1025 4.0325 1026 4.1938 1027 4.115 1028 4.813 1029 6.1941 1030 7.1323 1031 6.817 1032 5.7663 1033 6.3517 1034 5.6687 1035 5.2559 1036 5.6236 1037 5.3872 1038 5.9276 1039 5.6499 1040 5.7663 1041 5.9464 1042 6.2429 1043 7.3912 1044 4.753 1045 4.3927 1046 4.6442 1047 4.9969 1048 4.5166 1049 5.9089 1050 5.6236 1051 5.7325 1052 5.451 1053 6.2203 1054 5.8376 1055 6.0665 1056 6.3855 1057 6.393 1058 5.5448 1059 5.4135 1060 6.2992 1061 6.1978 1062 6.0702 1063 6.4605 1064 5.815 1065 5.0757 1066 5.1921 1067 5.2521 1068 5.3947 1069 5.5448 1070 5.8188 1071 5.4623 1072 5.9839 1073 5.5261 1074 5.5448 1075 5.5148 1076 6.7382 1077 7.7252 1078 6.3817 1079 6.9559 1080 6.0252 1081 5.7775 1082 7.1473 1083 6.3855 1084 7.6914 1085 7.6577 1086 7.061 1087 6.787 1088 6.7908 1089 6.787 1090 6.6144 1091 5.1095 1092 5.481 1093 5.8451 1094 4.6216 1095 6.2016 1096 6.727 1097 5.6086 1098 5.2896 1099 4.6404 1100 4.9707 1101 4.8243 1102 5.0345 1103 6.5243 1104 7.4025 1105 5.5186 1106 6.4418 1107 6.6894 1108 5.9989 1109 6.3404 1110 6.0027 1111 5.6424 1112 5.1358 1113 6.1415 1114 7.0122 1115 5.8563 1116 5.5899 1117 5.2146 1118 5.7437 1119 5.057 1120 5.4135 1121 4.4303 1122 4.4828 1123 5.5448 1124 6.0064 1125 5.0682 1126 5.2821 1127 5.2934 1128 5.5373 1129 6.2316 1130 5.7625 1131 6.2766 1132 6.817 1133 4.768 1134 4.07 1135 4.9556 1136 4.0024 1137 4.115 1138 4.1976 1139 4.3364 1140 4.434 1141 4.4603 1142 5.5111 1143 5.6086 1144 7.0535 1145 5.9089 1146 5.5674 1147 5.8301 1148 5.2221 1149 4.5804 1150 4.7192 1151 4.8656 1152 4.9857 1153 5.4247 1154 5.8713 1155 6.0477 1156 6.3217 1157 6.089 1158 5.5298 1159 5.5561 1160 4.9331 1161 6.1866 1162 5.6086 1163 6.0852 1164 5.7025 1165 5.6987 1166 5.8788 1167 6.7007 1168 5.785 1169 4.4152 1170 4.9219 1171 5.77 1172 4.7305 1173 4.0963 1174 4.8168 1175 4.753 1176 4.5128 1177 5.1996 1178 6.074 1179 6.4418 1180 5.0945 1181 6.4605 1182 4.6479 1183 5.4923 1184 5.1358 1185 5.9276 1186 5.3572 1187 5.755 1188 5.4022 1189 4.8281 1190 4.3477 1191 4.5091 1192 6.0064 1193 5.376 1194 6.2654 1195 5.3272 1196 4.9632 1197 6.2391 1198 5.2859 1199 5.6086 1200 5.9989 1201 6.1941 1202 5.725 1203 4.6442 1204 5.1733 1205 5.1358 1206 5.7437 1207 5.6424 1208 6.5581 1209 5.7738 1210 5.3534 1211 5.0119 1212 3.6947 1213 5.2934 1214 4.8581 1215 4.7492 1216 5.5899 1217 5.0832 1218 5.9014 1219 5.8451 1220 6.6594 1221 6.0852 1222 5.4022 1223 5.8263 1224 5.6161 1225 5.2821 1226 6.3554 1227 4.9669 1228 5.1996 1229 5.7325 1230 5.3985 1231 5.8601 1232 5.2221 1233 4.8243 1234 3.8861 1235 4.6367 1236 4.5879 1237 5.8225 1238 5.6799 1239 6.4005 1240 5.5298 1241 4.5053 1242 5.3009 1243 5.5448 1244 5.8413 1245 5.3234 1246 5.3947 1247 5.6612 1248 6.1941 1249 5.1996 1250 4.9782 1251 4.2163 1252 4.5316 1253 4.9782 1254 5.6874 1255 6.5694 1256 5.6011 1257 7.6802 1258 7.0647 1259 6.7795 1260 6.3217 1261 4.9669 1262 4.1375 1263 5.0232 1264 5.8451 1265 6.0402 1266 6.3104 1267 5.1545 1268 5.815 1269 7.0347 1270 6.2091 1271 6.1903 1272 5.9727 1273 7.3687 1274 5.9351 1275 6.5431 1276 6.6669 1277 6.1565 1278 5.0157 1279 4.6517 1280 4.6742 1281 5.9952 1282 6.2616 1283 5.9839 1284 5.6086 1285 6.2091 1286 5.5298 1287 5.3647 1288 4.9256 1289 5.1133 1290 5.695 1291 5.9877 1292 5.8826 1293 5.725 1294 6.4455 1295 6.408 1296 6.8658 1297 6.0027 1298 5.8451 1299 5.2033 1300 4.9969 1301 5.2296 1302 4.2163 1303 4.6367 1304 5.0757 1305 5.785 1306 5.9314 1307 7.3387 1308 5.4623 1309 6.378 1310 5.9877 1311 5.5974 1312 4.9331 1313 5.6987 1314 5.3497 1315 5.4022 1316 6.0064 1317 7.2036 1318 7.9354 1319 7.1023 1320 7.3012 1321 7.0122 1322 7.0197 1323 6.483 1324 5.5298 1325 6.0515 1326 5.8751 1327 5.6762 1328 6.2504 1329 5.6161 1330 6.0214 1331 6.423 1332 6.5393 1333 5.8901 1334 6.3142 1335 5.9727 1336 6.6482 1337 6.7045 1338 6.2241 1339 5.8676 1340 5.1883 1341 5.3384 1342 5.8376 1343 5.2634 1344 4.5091 1345 5.147 1346 5.5711 1347 5.102 1348 4.5166 1349 5.4323 1350 4.5954 1351 4.8693 1352 6.1228 1353 5.9501 1354 6.408 1355 5.4961 1356 5.7287 1357 5.0682 1358 5.5036 1359 5.3422 1360 5.3422 1361 4.5954 1362 4.9331 1363 4.9406 1364 5.7738 1365 5.421 1366 5.4247 1367 6.2879 1368 6.712 1369 4.6704 1370 6.2203 1371 5.1771 1372 5.5411 1373 5.1058 1374 5.5036 1375 5.1771 1376 5.5674 1377 4.5541 1378 5.7625 1379 6.2279 1380 6.1603 1381 6.9484 1382 7.6164 1383 6.3742 1384 6.5018 1385 7.2186 1386 7.6014 1387 6.8583 1388 4.9294 1389 5.5036 1390 5.9614 1391 7.0122 1392 6.2354 1393 6.8621 1394 6.5393 1395 4.7305 1396 5.3384 1397 4.9932 1398 4.7117 1399 4.5654 1400 4.07 1401 4.8543 1402 5.0795 1403 4.4565 1404 4.6179 1405 5.0007 1406 5.3572 1407 4.8843 1408 5.6199 1409 4.9857 1410 5.4735 1411 5.2859 1412 5.2071 1413 4.5391 1414 4.8431 1415 4.7793 1416 5.4585 1417 4.753 1418 5.147 1419 6.0365 1420 5.6987 1421 5.7813 1422 5.2596 1423 5.1958 1424 5.8788 1425 5.2746 1426 6.1791 1427 6.5356 1428 6.742 1429 6.1791 1430 5.8939 1431 6.1903 1432 6.3817 1433 5.3422 1434 5.5936 1435 5.4698 1436 6.0177 1437 5.6837 1438 6.5543 1439 6.2804 1440 5.0457 1441 5.0382 1442 5.0795 1443 5.2446 1444 4.5053 1445 4.8918 1446 5.6837 1447 5.2033 1448 4.7455 1449 5.4022 1450 4.5654 1451 5.0457 1452 5.4435 1453 5.3347 1454 4.5391 1455 4.7042 1456 4.7267 1457 4.8918 1458 5.9802 1459 6.2841 1460 7.0497 1461 6.7758 1462 6.0477 1463 5.0082 1464 5.7325 1465 5.5674 1466 4.2576 1467 5.755 1468 5.3835 1469 4.6517 1470 5.3797 1471 4.9069 1472 4.7567 1473 6.0214 1474 4.783 1475 4.7643 1476 4.9782 1477 4.4265 1478 5.4097 1479 4.8581 1480 4.4002 1481 4.9069 1482 6.2954 1483 6.059 1484 5.1921 1485 6.3554 1486 5.6274 1487 5.2784 1488 6.9972 1489 6.3667 1490 5.8676 1491 5.3384 1492 5.1621 1493 4.8318 1494 4.8731 1495 4.6104 1496 5.6312 1497 5.6011 1498 5.4022 1499 6.1078 1500 6.2804 1501 5.4247 1502 5.3722 1503 5.5298 1504 6.0702 1505 5.0945 1506 5.4585 1507 5.376 1508 5.0007 1509 4.5091 1510 5.0983 1511 6.1228 1512 6.6519 1513 5.8826 1514 6.2615 1515 5.2631 1516 4.7451 1517 5.7736 1518 5.3679 1519 5.8697 1520 5.9835 1521 5.6508 1522 5.6306 1523 6.9856 1524 6.3241 1525 5.7921 1526 6.2056 1527 5.2835 1528 4.9166 1529 5.8155 1530 6.2462 1531 5.6552 1532 4.9877 1533 5.3498 1534 5.3582 1535 6.6656 1536 6.3431 1537 6.489 1538 5.8765 1539 6.2579 1540 5.6619 1541 5.7943 1542 4.3314 1543 4.7155 1544 6.1067 1545 6.5465 1546 6.2328 1547 6.1661 1548 5.7111 1549 5.2542 1550 5.6718 1551 6.7606 1552 5.0123 1553 5.5222 1554 5.7298 1555 5.8589 1556 6.2425 1557 5.066 1558 6.967 1559 6.9293 1560 5.9969 1561 6.315 1562 6.0867 1563 5.6598 1564 6.295 1565 6.4308 1566 5.7444 1567 4.5362 1568 4.6701 1569 3.7337 1570 4.2964 1571 3.86 1572 3.8132 1573 5.284 1574 5.6964 1575 6.0877 1576 5.4608 1577 5.8324 1578 6.4821 1579 5.7962 1580 5.2402 1581 5.6873 1582 6.4853 1583 5.9183 1584 5.1545 1585 4.2765 1586 5.5278 1587 4.9873 1588 5.094 1589 5.2085 1590 5.7493 1591 6.307 1592 5.9234 1593 6.0121 1594 6.3583 1595 5.6115 1596 5.4047 1597 6.5965 1598 5.0617 1599 5.1141 1600 4.8183 1601 4.4106 1602 4.1342 1603 4.7157 1604 4.3117 1605 4.2334 1606 4.9835 1607 6.1726 1608 6.4699 1609 6.6614 1610 6.7446 1611 5.7484 1612 6.0476 1613 4.7185 1614 5.4695 1615 4.6668 1616 5.7825 1617 6.0641 1618 4.7257 1619 5.9791 1620 4.8319 1621 5.8928 1622 5.5962 1623 4.715 1624 4.6058 1625 5.0032 1626 4.9714 1627 5.6825 1628 5.5905 1629 5.4576 1630 6.0329 1631 5.9671 1632 7.4561 1633 6.7675 1634 6.9477 1635 7.1482 1636 6.0092 1637 6.1687 1638 6.0077 1639 4.8511 1640 5.9161 1641 5.4039 1642 5.012 1643 5.2846 1644 4.8591 1645 5.94 1646 5.8829 1647 5.9165 1648 6.2106 1649 5.9033 1650 6.8373 1651 7.0423 1652 5.4937 1653 5.4747 1654 5.3336 1655 5.2338 1656 5.5887 1657 5.7044 1658 4.8267 1659 5.077 1660 5.0326 1661 4.7506 1662 4.446 1663 3.7218 1664 4.6583 1665 4.5939 1666 5.4756 1667 5.7925 1668 6.019 1669 5.5611 1670 5.7932 1671 5.9466 1672 5.5813 1673 5.5317 1674 4.7139 1675 4.8831 1676 5.0084 1677 3.3848 1678 3.6654 1679 3.3729 1680 4.6026 1681 5.1479 1682 5.9124 1683 7.3263 1684 7.2937 1685 7.4979 1686 6.8063 1687 6.9753 1688 6.4943 1689 6.75 1690 5.8607 1691 5.553 1692 6.992 1693 6.6325 1694 7.2046 1695 6.593 1696 5.2075 1697 3.3692 1698 2.9377 1699 2.9115 1700 4.1242 1701 4.9461 1702 4.7473 1703 5.6942 1704 4.9664 1705 5.1612 1706 4.8322 1707 5.9292 1708 5.9021 1709 5.6142 1710 5.0417 1711 4.8152 1712 6.1616 1713 5.8562 1714 5.5662 1715 6.2512 1716 3.9028 1717 5.1648 1718 6.3699 1719 7.4866 1720 6.7384 1721 7.3929 1722 7.2063 1723 7.4276 1724 6.7948 1725 6.3391 1726 5.6577 1727 5.5441 1728 6.975 1729 6.678 1730 6.0827 1731 6.1871 1732 6.5421 1733 6.2652 1734 5.1648 1735 5.2043 1736 5.5854 1737 6.0449 1738 4.9343 1739 6.2594 1740 6.0038 1741 5.9978 1742 5.8282 1743 5.7036 1744 4.9008 1745 5.4 1746 4.7007 1747 5.8608 1748 5.7801 1749 6.7182 1750 7.1107 1751 6.7531 1752 4.9881 1753 5.1903 1754 3.497 1755 3.9716 1756 3.6497 1757 4.4953 1758 5.2508 1759 5.1312 1760 6.4802 1761 6.8403 1762 7.7825 1763 7.2399 1764 6.3172 1765 7.3782 1766 6.1341 1767 6.5054 1768 4.9169 1769 5.4927 1770 5.7311 1771 5.226 1772 5.4696 1773 6.1104 1774 6.0972 1775 5.1765 1776 5.5619 1777 5.6854 1778 5.1297 1779 6.4631 1780 6.1494 1781 5.9051 1782 6.0097 1783 6.0053 1784 6.1505 1785 5.7477 1786 5.307 1787 5.662 1788 5.5511 1789 5.2344 1790 5.0187 1791 5.732 1792 6.6516 1793 6.1761 1794 6.8065 1795 7.1509 1796 6.3584 1797 7.0757 1798 5.8922 1799 5.8918 1800 4.8731 1801 5.6086 1802 5.8645 1803 6.1784 1804 7.176 1805 6.8028 1806 5.9982 1807 6.0874 1808 6.3591 1809 4.4931 1810 5.2143 1811 4.5666 1812 4.5531 1813 4.1852 1814 3.98 1815 5.285 1816 5.6151 1817 5.3103 1818 5.7857 1819 5.4619 1820 5.7023 1821 5.6019 1822 6.6388 1823 5.6621 1824 6.7976 1825 7.6058 1826 6.0658 1827 5.6944 1828 6.7935 1829 7.329 1830 4.5181 1831 5.2094 1832 5.7929 1833 5.613 1834 5.0659 1835 6.0687 1836 5.6545 1837 6.0772 1838 6.1241 1839 6.1915 1840 6.4904 1841 4.8872 1842 4.2908 1843 4.7259 1844 4.2976 1845 4.5143 1846 5.097 1847 5.2833 1848 4.6276 1849 4.586 1850 4.1978 1851 4.8426 1852 4.4141 1853 3.9361 1854 4.9399 1855 4.5049 1856 4.4614 1857 5.0718 1858 5.3082 1859 5.2179 1860 4.9716 1861 4.8325 1862 3.8521 1863 4.1829 1864 3.9552 1865 3.9749 1866 4.3186 1867 4.7942 1868 4.9173 1869 4.4793 1870 5.118 1871 4.5832 1872 5.7464 1873 5.3531 1874 5.2868 1875 5.3248 1876 4.8352 1877 4.8455 1878 5.3821 1879 5.2645 1880 5.2707 1881 5.8167 1882 5.5085 1883 5.9491 1884 6.6591 1885 5.9895 1886 5.7528 1887 5.2946 1888 6.0097 1889 6.2066 1890 5.958 1891 6.1171 1892 6.0987 1893 6.135 1894 4.3027 1895 4.5556 1896 4.911 1897 4.8252 1898 5.2899 1899 6.03 1900 6.5005 1901 6.7217 1902 6.3893 1903 5.4611 1904 5.2322 1905 6.2239 1906 5.8194 1907 5.2688 1908 5.2915 1909 5.3185 1910 5.6051 1911 5.6809 1912 5.6426 1913 6.2572 1914 6.6907 1915 8.1293 1916 6.6383 1917 6.1877 1918 5.7418 1919 5.1459 1920 5.5902 1921 6.0619 1922 5.4551 1923 6.675 1924 6.2856 1925 6.2142 1926 7.3747 1927 6.3492 1928 5.9942 1929 6.0371 1930 5.869 1931 6.305 1932 6.0607 1933 6.6341 1934 5.9782 1935 6.2175 1936 5.9309 1937 5.144 1938 5.2755 1939 5.4433 1940 6.506 1941 6.835 1942 7.2699 1943 6.8809 1944 6.616 1945 6.2468 1946 6.3381 1947 5.8389 1948 5.4016 1949 5.3725 1950 5.5947 1951 5.1257 1952 5.2659 1953 5.3345 1954 5.3281 1955 5.0963 1956 5.0363 1957 5.969 1958 5.5335 1959 5.5949 1960 5.7865 1961 5.8472 1962 6.1851 1963 6.6175 1964 6.1522 1965 5.9021 1966 5.9719 1967 5.3973 1968 5.8611 1969 5.4233 1970 5.4357 1971 5.3322 1972 4.3272 1973 3.8668 1974 5.186 1975 5.0818 1976 5.517 1977 5.9949 1978 5.9314 1979 6.9414 1980 6.01 1981 7.016 1982 6.3343 1983 6.5694 1984 6.6645 1985 6.1524 1986 6.1336 1987 5.8861 1988 6.1143 1989 6.3799 1990 5.9936 1991 5.8353 1992 6.0496 1993 6.802 1994 6.5613 1995 6.0559 1996 6.6229 1997 6.1547 1998 6.1243 1999 5.7808