# Southern Annular Mode (SAM) Index 600 Year Tree Ring Reconstruction #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite original reference when using these data, # plus the Online Resource and date accessed. # # # Online_Resource: http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:13673 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/villalba2012sam-crns.txt # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Climate Reconstructions #-------------------- # Contribution_Date # Date: 2013-01-07 #-------------------- # Title # Study_Name: Southern Annular Mode (SAM) Index 600 Year Tree Ring Reconstruction #-------------------- # Investigators # Investigators: Villalba, R.; Lara, A.; Masiokas, M.H.; Urrutia, R.; Luckman, B.H.; Marshall, G.J.; Mundo, I.A.; Christie, D.A.; Cook, E.R.; Neukom, R.; Allen, K.; Fenwick, P.; Boninsegna, J.A.; Srur, A.M.; Morales, M.S.; Araneo, D.; Palmer, J.G.; Cuq, E.; Aravena, J.C.; Holz, A.; LeQuesne, C. #-------------------- # Description_and_Notes # # Southern Annular Mode (SAM) Index reconstruction for the past 600 years based on 3000 trees from 102 sites # across South America, Tasmania and New Zealand. We identified regional tree growth patterns for the temperate # forests in these three regions during the past 400-600 years. Using time-varying subsets of regional # chronologies as predictors, we develop two reconstructions of mean summer (December-February) SAM variations # for the period 1409-2006. Two instrumental target series were selected for analysis: the SAM-Marshall # (based on selected station pressure records) and the SAM-NCEP (based on mean sea-level pressure south of 20S). # The first principal component (PC1) of the three regional chronologies best correlated with the predictands # explains 44 and 47% of the total variance of the SAM-Marshall and SAM-NCEP instrumental records, respectively. # # Data set updated 28 July 2014 with addition of underlying tree-ring chronolology and raw ringwidth data. # Added files include a). villalba2012sam.xls, an Excel format file containing the SAM reconstruction and # all tree-ring chronologies; b.) text data file villalba2012sam-crns.txt containing the 3 chronology predictor series; # c.) 6 raw ring width tree ring data files used to develop the chronologies listed in SI_Table 2 (Regional tree-ring # chronologies): # villalba2012sam-araucaria.txt, villalba2012sam-austrocedrus.txt, villalba2012sam-halocarpus.txt, # villalba2012sam-lagarostrobos.txt, villalba2012sam-nothofagus.txt, and villalba2012sam-phyllocadus.txt. # # These tree ring data make it possible to validate the SAM reconstructions starting from the regional chronologies # (included on the Excel file) or from the raw data contained in the raw measurement files. This is all the data # used to support the conclusions of the Nature Geoscience paper. Regional chronologies were developed by combining # some of the individual chronologies listed in SI_Table 1 (Tree-ring chronologies). Those chronologies not included # in the Regional chronologies can be obtained by contacting the producers listed in Source of SA_Table 1. # Most of these chronologies are presently included in the International Tree-Ring Data Bank. # #-------------------- # Publication # Authors: Ricardo Villalba, Antonio Lara, Mariano H. Masiokas, Rocío Urrutia, Brian H. Luckman, Gareth J. Marshall, Ignacio A. Mundo, Duncan A. Christie, Edward R. Cook, Raphael Neukom, Kathryn Allen, Pavla Fenwick, José A. Boninsegna, Ana M. Srur, Mariano S. Morales, Diego Araneo, Jonathan G. Palmer, Emilio Cuq, Juan C. Aravena, Andrés Holz, and Carlos LeQuesne # Published_Date_or_YEAR: 2012-11-01 # Published_Title: Unusual Southern Hemisphere tree growth patterns induced by changes in the Southern Annular Mode # Journal_Name: Nature Geoscience # Volume: 5 # Issue: 11 # Pages: 793-798 # DOI: 10.1038/NGEO1613 # Abstract: Recent changes in the summer climate of the Southern Hemisphere extra-tropics are primarily related to the dominance of the positive phase of the Southern Annular Mode. This shift in the behaviour of the Southern Annular Mode - essentially a measure of the pressure gradient between Southern Hemisphere mid and high latitudes - has been predominantly induced by polar stratospheric ozone depletion. The concomitant southward expansion of the dry subtropical belts could have consequences for forest growth. Here, we use tree-ring records from over 3,000 trees in South America, Tasmania and New Zealand to identify dominant patterns of tree growth in recent centuries. We show that the foremost patterns of growth between 1950 and 2000 differed significantly from those in the previous 250 years. Specifically, growth was higher than the long-term average in the subalpine forests of Tasmania and New Zealand, but lower in the dry-mesic forests of Patagonia. We further demonstrate that variations in the Southern Annular Mode can explain 12-48% of the tree growth anomalies in the latter half of the twentieth century. Tree-ring-based reconstructions of summer Southern Annular Mode indices suggest that the high frequency of the positive phase since the 1950s is unprecedented in the past 600 years. We propose that changes in the Southern Annular Mode have significantly altered tree growth patterns in the Southern Hemisphere. # #--------------------- # Funding_Agency # Funding_Agency_Name: Inter-American Institute for Global Change Research (IAI) # Grant: CRN 2047 #--------------------- # Funding_Agency_Name: US National Science Foundation # Grant: GEO-0452325 #--------------------- # Funding_Agency_Name: Argentinean Council of Research and Technology (CONICET) # Grant: #--------------------- # Funding_Agency_Name: Argentinean Agency for Promotion of Science and Technology # Grant: PICTR02-186 #--------------------- # Funding_Agency_Name: National Research Fund of Chile # Grant: FONDECYT 1090479 and 1120965 #-------------------- # Funding_Agency_Name: UK Natural Environment Research Council # Grant: BAS Polar Science for Planet Earth #-------------------- # Funding_Agency_Name: Australian Research Council # Grant: DP120104320 #-------------------- # Site_Information # Site_Name: # Location: # Country: # Northernmost_Latitude: -20 # Southernmost_Latitude: -90 # Easternmost_Longitude: -180 # Westernmost_Longitude: 180 # Elevation: m #------------------ # Data_Collection # Core_Name: Villalba2012SAM-crns # First_Year: 1409 # Last_Year: 2007 # Time_Unit: AD # Core_Length: # Notes: #------------------ year Austrocedrus Araucaria Halocarpus 1409 1.056 1410 1.149 1411 0.976 1412 0.865 1413 1.082 1414 1.013 1415 1.038 1416 0.907 1417 0.805 1418 0.873 1419 0.96 1420 0.921 1421 0.905 1422 0.938 1423 1.184 1424 0.888 1425 1.131 1426 1.243 1427 1.149 1428 1.145 1429 1.134 1430 0.924 1431 0.827 1432 0.989 1433 1.225 1434 1.01 1435 1.082 1436 1.07 1437 1.023 1438 0.966 1439 0.801 1440 1.066 1441 0.949 1442 1.06 1443 1 1444 1.029 1445 1.094 1446 1.039 1447 0.87 1448 1.151 1449 1.069 1450 1.088 1451 1.144 1452 0.969 1453 1.211 1454 1.163 1455 1.037 1456 0.932 1457 0.832 1458 1.063 1459 1.092 1460 1.278 1461 1.043 1462 1.327 1463 1.158 1464 1.152 1465 1.314 1466 1.236 1467 1.134 1468 1.057 1469 1.213 1470 1.294 1471 1.285 1472 1.433 1473 1.38 1474 1.405 1475 1.332 1476 1.326 1477 1.211 1478 1.204 1479 1.354 1480 1.105 1481 1.226 1482 1.277 1483 1.086 1484 1.269 1485 1.322 1486 1.073 0.874 1487 1.113 1.05 1488 1.154 0.935 1489 1.241 0.825 1490 1.216 0.857 1491 1.002 0.835 1492 1.11 0.837 1493 1.029 0.929 1494 0.837 0.913 1495 1.137 0.998 1496 1.112 0.859 1497 1.037 0.893 1498 0.954 0.711 1499 0.953 0.706 1500 0.921 0.96 1501 1.076 1.141 1502 1.031 1.012 1503 0.915 0.808 1504 1.098 0.865 1505 1.183 0.792 1506 1.062 0.883 1507 1.148 0.684 1508 0.998 0.655 1509 1.238 0.705 1510 1.033 0.597 1511 0.776 0.748 1512 0.989 0.854 1513 0.91 0.891 1514 0.953 0.653 1515 1.095 0.854 1516 0.889 0.974 1517 1.095 0.767 1518 0.87 0.575 1519 0.828 0.564 1520 0.836 0.644 1521 0.88 0.592 1522 1.15 0.816 1523 1.085 0.908 1524 1.16 0.79 1525 1.208 0.655 1526 1.114 0.698 1527 0.941 0.827 1528 0.983 0.919 1529 1.049 0.876 1530 0.92 0.962 1531 1.012 1.02 1532 1.063 1.105 1533 1.039 1.085 1534 1.158 0.859 1535 1.187 0.778 1536 1.188 0.747 1537 1.065 0.682 1538 1.228 0.808 1539 1.002 0.818 1540 1.074 0.866 1541 1.264 0.896 1542 1.302 0.769 1543 1.238 0.793 1544 1.126 0.751 1545 0.999 0.826 1546 0.971 0.934 1547 1.113 1.017 1548 0.989 0.951 1549 1.05 1.066 1550 1.324 1.033 1551 1.157 0.857 1552 1.003 1.006 1553 1.072 0.873 1554 1.064 0.696 1555 0.945 0.793 1556 1.029 0.734 1557 1.084 0.776 1558 1.261 0.695 1559 1.365 1.109 0.568 1560 1.253 1.061 0.706 1561 1.296 1.234 0.625 1562 1.33 1.142 0.707 1563 1.385 1.116 0.555 1564 1.219 0.921 0.576 1565 1.152 0.83 0.544 1566 1.18 0.929 0.83 1567 1.407 1.072 0.804 1568 1.417 1.048 0.953 1569 1.43 1.187 1.094 1570 1.339 1.033 1.061 1571 1.532 0.92 1.092 1572 1.347 0.908 1.236 1573 1.258 0.942 1.122 1574 1.406 1.059 0.799 1575 1.24 1.026 0.901 1576 1.074 0.814 0.988 1577 1.21 1.114 0.971 1578 1.081 0.939 0.968 1579 1.034 1.086 0.975 1580 1.057 1.057 1.025 1581 1.058 1.262 1.026 1582 0.848 1.186 0.975 1583 1.11 1.112 0.796 1584 1.347 1.285 0.832 1585 1.264 1.265 0.978 1586 1.304 1.182 0.949 1587 1.279 1.262 1.038 1588 1.222 1.22 0.931 1589 1.52 1.107 1.031 1590 1.511 1.2 0.803 1591 1.461 1.25 0.724 1592 1.207 1.135 0.872 1593 1.272 0.976 0.788 1594 1.152 1.15 0.741 1595 0.947 1.128 0.773 1596 1.265 1.255 0.648 1597 1.343 1.036 0.651 1598 1.245 1.049 0.823 1599 0.855 0.915 0.886 1600 1.38 1.095 0.823 1601 1.321 1.16 0.954 1602 1.152 1.052 1.064 1603 1.033 1.003 1.116 1604 1.248 0.893 1.021 1605 1.442 0.957 0.985 1606 1.367 0.986 0.843 1607 1.317 0.926 0.702 1608 1.095 0.905 0.906 1609 1.346 1.146 0.737 1610 1.245 1.292 0.837 1611 1.029 1.034 0.947 1612 1.08 0.889 1.008 1613 1.223 1.013 1.061 1614 1.192 1.074 0.892 1615 1.052 1.078 0.856 1616 1.171 1.094 0.841 1617 1.266 1.087 0.919 1618 1.297 1.02 0.919 1619 1.4 1.123 0.789 1620 1.229 1.068 0.786 1621 1.28 1.122 0.81 1622 1.124 1.096 0.872 1623 1.164 1.135 0.84 1624 1.12 0.941 0.841 1625 0.977 0.919 0.856 1626 1.044 1.037 0.969 1627 1.162 0.822 1.015 1628 1.154 1.056 1.02 1629 0.982 0.904 0.99 1630 1.163 1.03 1.01 1631 1.091 1.099 0.74 1632 0.951 0.92 1.041 1633 1.065 1.063 0.84 1634 1.154 1.085 0.445 1635 1.38 1.154 0.617 1636 1.304 1.267 0.849 1637 1.173 1.083 0.946 1638 1.194 1.159 0.885 1639 1.103 0.985 0.69 1640 1.14 0.917 0.954 1641 1.169 0.989 0.934 1642 1.308 1.058 0.829 1643 1.296 1.114 1.109 1644 1.137 0.933 1.037 1645 0.895 0.977 0.934 1646 0.779 0.967 0.754 1647 0.895 1.002 0.838 1648 1.198 1.175 0.889 1649 1.052 1.103 0.911 1650 1.034 1.147 0.73 1651 1.076 0.786 0.78 1652 1.334 1.099 0.975 1653 1.424 1.084 0.95 1654 1.398 1.125 0.907 1655 0.903 0.931 0.885 1656 1.03 0.921 0.794 1657 1.038 0.959 0.918 1658 1.296 1.16 0.885 1659 1.313 1.058 0.823 1660 1.188 1.074 0.62 1661 1.154 0.92 0.745 1662 1.122 0.794 0.871 1663 1.097 1.125 0.793 1664 0.88 0.957 0.751 1665 0.912 0.904 0.716 1666 1.047 0.898 1 1667 0.977 0.922 0.793 1668 1.142 1.045 0.983 1669 0.993 0.98 0.852 1670 1.058 1.091 0.917 1671 1.173 1.102 0.975 1672 1.081 1.07 0.908 1673 0.998 1.006 0.932 1674 1.226 1.116 1.036 1675 1.139 0.86 0.95 1676 1.049 1.029 0.708 1677 1.02 1.05 0.883 1678 1.11 1.176 0.921 1679 1.229 1.107 0.83 1680 1.089 0.958 0.814 1681 0.828 0.972 0.889 1682 0.512 0.816 0.958 1683 0.758 1.016 0.831 1684 1.009 1.109 0.858 1685 1.037 1.091 0.967 1686 0.94 0.933 0.979 1687 0.996 0.972 1.121 1688 1.124 1.022 1.129 1689 1.136 0.964 1.041 1690 1.155 0.98 1.169 1691 1.006 0.988 0.995 1692 1.053 1.008 0.857 1693 0.922 0.935 1.124 1694 1.14 1.19 0.938 1695 1.137 1.046 0.811 1696 1.153 0.847 1.015 1697 1.193 0.915 0.97 1698 1.03 0.978 0.953 1699 0.968 0.937 0.949 1700 0.991 1.109 0.768 1701 0.962 1.162 0.879 1702 0.913 1.186 0.812 1703 1.18 1.24 0.932 1704 1.289 1.203 0.955 1705 0.901 0.982 0.867 1706 0.904 1.014 0.896 1707 1.129 1.062 0.914 1708 1.225 1.154 0.809 1709 1.159 1.188 0.876 1710 1 0.989 0.774 1711 1.048 1.046 0.971 1712 1.1 1.026 1.095 1713 1.035 1.048 1.005 1714 0.961 1.01 1.109 1715 1.088 1.122 1.143 1716 0.927 0.889 1.194 1717 0.82 0.98 0.991 1718 0.786 0.974 0.835 1719 0.907 0.76 0.846 1720 1.224 1.226 0.952 1721 1.066 1.19 0.939 1722 1.042 1.005 0.834 1723 1.124 1.092 0.935 1724 1.212 1.085 1.11 1725 1.164 1.142 1.003 1726 1.176 1.08 0.867 1727 1.185 0.91 0.985 1728 1.317 1.048 1.041 1729 1.12 0.99 0.926 1730 1.033 1.074 1.093 1731 1.151 1.07 1.18 1732 1.156 1.069 1.11 1733 1.021 1.017 1.074 1734 1.1 1.002 1.032 1735 1.052 1.014 1.085 1736 1.013 1.173 1.047 1737 0.884 0.901 0.92 1738 0.897 1.041 0.966 1739 1.09 1.087 1.1 1740 1.089 1.161 1.107 1741 1.185 1.094 1.124 1742 1.167 1.164 1.296 1743 1.032 0.843 1.265 1744 1.137 0.911 1.07 1745 0.864 1.005 0.859 1746 0.807 1.103 1.056 1747 0.746 1.029 1.057 1748 0.94 1.001 1.187 1749 1.189 1.358 0.987 1750 1.147 1.201 0.885 1751 0.938 0.98 1.149 1752 0.909 0.958 1.268 1753 1.049 1.016 1.2 1754 1.045 1.051 1.007 1755 0.88 0.995 1.078 1756 1.054 1.117 1.171 1757 1.069 1.147 1.185 1758 1.037 1.199 1.048 1759 0.996 1.138 1.035 1760 1.28 1.152 0.966 1761 1.212 1.183 1.05 1762 0.862 0.969 1.044 1763 1.095 1.065 0.873 1764 1.075 1.006 0.826 1765 0.963 0.988 0.845 1766 1.147 1 0.925 1767 0.907 0.855 0.954 1768 1.042 0.872 0.845 1769 1.031 1.101 0.824 1770 0.941 1.012 0.829 1771 1.043 1.037 0.973 1772 1.023 0.828 0.931 1773 1.058 0.948 1.038 1774 1.192 0.954 0.998 1775 1.214 0.926 0.878 1776 1.171 0.994 0.892 1777 1.24 0.934 1.053 1778 1.127 1.008 0.989 1779 1.007 0.84 0.984 1780 1.01 0.891 1.018 1781 1.203 1.135 1.063 1782 1.034 1.1 0.89 1783 0.899 0.902 0.963 1784 1.164 1.124 0.96 1785 1.039 1.016 0.994 1786 0.955 0.913 1.116 1787 0.979 0.901 1.121 1788 1.177 1.066 1.009 1789 1.138 0.885 0.956 1790 1.212 1.09 0.882 1791 1.118 1.061 0.684 1792 1.051 0.977 0.712 1793 1.034 1.077 0.873 1794 1.034 1.22 0.868 1795 0.931 1.111 0.834 1796 0.943 1.2 1.075 1797 1.201 1.203 1.133 1798 1.078 1.108 0.895 1799 1.001 1.029 0.743 1800 1.091 1.153 1.06 1801 1.022 0.855 1.057 1802 0.933 0.927 1.172 1803 1.035 0.972 1.024 1804 0.921 1.039 1.082 1805 0.906 0.894 1.204 1806 0.888 0.906 0.873 1807 0.859 0.786 0.656 1808 1.167 0.932 1.115 1809 1.176 1.079 1.012 1810 1.125 0.937 1.066 1811 1.185 0.816 1.088 1812 1.177 0.955 1.055 1813 0.645 0.685 0.933 1814 0.853 0.919 1.028 1815 0.928 0.95 0.978 1816 1.003 1.037 0.99 1817 0.983 1.033 0.86 1818 0.999 0.918 0.895 1819 0.809 0.787 0.964 1820 0.681 0.907 0.86 1821 0.653 0.877 1.013 1822 0.931 0.973 0.909 1823 1.051 0.974 0.972 1824 0.973 0.99 0.828 1825 1.013 0.92 1.072 1826 0.932 1.047 0.84 1827 0.759 0.947 0.947 1828 0.875 1.063 0.854 1829 1.106 1.094 0.91 1830 1.166 1.062 1.11 1831 1.079 1.112 1.1 1832 1.046 1.159 0.834 1833 1.098 1.136 0.597 1834 1.271 1.127 0.991 1835 1.071 1.122 1.028 1836 0.925 0.966 0.925 1837 1.122 1.136 0.921 1838 1.111 1.182 0.861 1839 0.922 0.804 0.772 1840 1.018 0.964 0.991 1841 0.722 0.778 1.038 1842 0.984 0.87 0.985 1843 1.224 0.967 0.969 1844 1.147 1.052 1.068 1845 0.703 0.959 0.992 1846 0.941 0.993 0.896 1847 0.904 0.953 1.074 1848 1.095 0.962 1.051 1849 1.063 1.071 1.137 1850 1.003 1.012 1.313 1851 0.893 0.921 1.292 1852 1.164 1.091 1.111 1853 1.054 0.905 1.22 1854 0.941 0.928 1.204 1855 1.073 0.962 1.161 1856 1.166 0.978 0.957 1857 1.186 1.061 0.907 1858 1.057 1.003 0.903 1859 0.863 0.831 1.013 1860 0.944 0.949 1.14 1861 0.835 0.818 1.29 1862 0.959 0.945 1.239 1863 1.144 1.013 1.156 1864 0.978 1 1.114 1865 0.762 0.85 1.01 1866 0.921 0.947 1.128 1867 0.967 0.805 0.998 1868 1.237 1.113 0.893 1869 1.255 0.973 1.038 1870 1.253 0.937 1.091 1871 1.008 0.882 1.071 1872 1.176 1.042 1.089 1873 1.137 0.955 1.254 1874 1.096 0.875 1.228 1875 0.965 0.655 1.24 1876 1.046 1.043 1.245 1877 0.722 0.856 1.103 1878 1.045 0.901 0.699 1879 1.205 0.802 1.248 1880 1.058 1.057 1.176 1881 0.971 1.006 1.145 1882 0.985 1.006 1.169 1883 0.972 0.981 1.071 1884 0.948 1.075 0.916 1885 0.948 0.886 1.153 1886 0.993 1.023 1.143 1887 0.985 1.009 0.976 1888 1.082 0.812 0.841 1889 1.133 0.717 1.019 1890 1.083 0.752 0.966 1891 1.032 0.808 1.038 1892 1.103 0.899 1.102 1893 0.758 0.687 1.034 1894 0.984 0.818 1.113 1895 0.982 0.898 1.039 1896 0.875 0.813 1.068 1897 0.895 0.605 0.897 1898 1.156 1.046 0.773 1899 1.045 1.059 0.891 1900 1.002 1.061 0.917 1901 0.881 1.079 0.856 1902 0.926 1.042 0.778 1903 0.927 1.201 0.803 1904 0.869 1.173 0.985 1905 0.953 0.988 0.831 1906 0.878 0.828 0.892 1907 0.982 0.993 1.015 1908 0.884 0.884 1.072 1909 0.865 0.688 1.129 1910 0.915 1.021 1.108 1911 0.72 0.937 0.892 1912 0.874 0.929 0.728 1913 0.654 0.809 1.022 1914 0.706 0.915 0.831 1915 0.919 0.92 0.943 1916 0.944 0.93 1.141 1917 0.761 0.847 1.129 1918 1.003 0.98 0.987 1919 0.854 0.926 0.897 1920 1.093 0.869 1.122 1921 1.104 1.069 1.174 1922 0.847 1.082 1.125 1923 0.792 1.129 1.172 1924 0.821 0.955 1.215 1925 0.95 1.094 0.986 1926 1.146 1.191 0.953 1927 0.945 1.037 1.234 1928 1.104 1.058 1.005 1929 1.116 1.193 0.968 1930 1.11 0.966 0.817 1931 1.006 1.064 0.748 1932 0.947 1.02 1.025 1933 1.138 1.198 0.903 1934 0.989 1.099 1.127 1935 1.098 1.035 1.029 1936 1.091 0.873 0.919 1937 1.018 0.773 0.863 1938 1.155 1.088 0.966 1939 1.098 1.014 0.863 1940 1.167 1.093 1.022 1941 1.272 1.027 0.976 1942 1.129 0.929 0.851 1943 0.641 0.922 0.883 1944 0.78 0.98 0.833 1945 1.221 0.87 0.759 1946 1.334 1.075 0.854 1947 1.043 0.937 0.902 1948 1.073 1.032 0.959 1949 0.955 0.906 0.913 1950 0.928 1.021 1.076 1951 1.127 1.129 0.88 1952 0.999 0.831 0.881 1953 0.896 0.916 0.991 1954 0.933 0.977 1.164 1955 1.053 0.847 1.238 1956 0.963 0.965 1.276 1957 0.692 0.821 1.118 1958 0.834 0.76 1.221 1959 0.841 0.872 1.304 1960 0.854 0.737 1.374 1961 0.888 0.913 1.251 1962 0.576 0.682 1.282 1963 0.899 0.887 1.212 1964 1.075 1.023 1.019 1965 1.119 0.891 1.245 1966 1.11 0.848 1.229 1967 0.942 0.733 1.246 1968 0.942 0.798 1.149 1969 0.876 0.845 1.182 1970 0.945 0.673 1.422 1971 1.028 0.998 1.432 1972 0.961 0.755 1.205 1973 1.004 0.682 1.307 1974 1.047 0.885 1.372 1975 1.078 0.877 1.198 1976 1.009 0.853 1.039 1977 1.066 0.846 1.179 1978 0.86 0.811 1.2 1979 0.86 0.844 1.208 1980 1.065 0.741 1.241 1981 0.9 0.762 1.218 1982 0.896 0.903 1.128 1983 0.843 0.921 0.954 1984 1.058 1.037 1.211 1985 1.015 1.106 1.273 1986 0.966 0.903 1.145 1987 0.836 0.738 1.177 1988 0.857 0.8 1.158 1989 0.708 0.838 1.327 1990 0.755 0.808 1.254 1991 0.904 0.912 1.101 1992 0.97 0.938 1.08 1993 1.06 0.855 1.185 1994 0.783 0.83 1.202 1995 0.694 0.827 1.24 1996 0.645 0.814 1.301 1997 0.818 0.756 1.368 1998 0.542 0.636 1.463 1999 0.364 0.569 1.485 2000 0.808 0.747 2001 0.766 0.75 2002 0.67 0.724 2003 0.852 0.737 2004 0.592 2005 0.617 2006 0.593