Year Measure 1800 961.5 1801 961.5 1802 961.5 1803 961.5 1804 961.5 1805 961.5 1806 961.5 1807 961.5 1808 961.5 1809 961.5 1810 961.5 1811 961.5 1812 961.5 1813 961.5 1814 961.5 1815 961.5 1816 961.5 1817 961.5 1818 961.5 1819 961.5 1820 961.5 1821 967.9 1822 974.3 1823 980.7 1824 987.2 1825 993.7 1826 1000 1827 1007 1828 1014 1829 1020 1830 1027 1831 1034 1832 1041 1833 1047 1834 1054 1835 1061 1836 1068 1837 1075 1838 1083 1839 1090 1840 1097 1841 1104 1842 1111 1843 1119 1844 1126 1845 1134 1846 1141 1847 1149 1848 1156 1849 1164 1850 1172 1851 1179 1852 1187 1853 1195 1854 1203 1855 1211 1856 1219 1857 1227 1858 1235 1859 1243 1860 1251 1861 1260 1862 1268 1863 1276 1864 1285 1865 1293 1866 1302 1867 1310 1868 1319 1869 1328 1870 1337 1871 1345 1872 1354 1873 1363 1874 1372 1875 1381 1876 1390 1877 1400 1878 1409 1879 1418 1880 1428 1881 1437 1882 1446 1883 1456 1884 1466 1885 1475 1886 1485 1887 1495 1888 1505 1889 1515 1890 1525 1891 1535 1892 1545 1893 1555 1894 1565 1895 1576 1896 1586 1897 1597 1898 1607 1899 1618 1900 1629 1901 1639 1902 1650 1903 1661 1904 1672 1905 1683 1906 1694 1907 1705 1908 1717 1909 1728 1910 1739 1911 1751 1912 1762 1913 1774 1914 1801 1915 1827 1916 1855 1917 1882 1918 1910 1919 1939 1920 1968 1921 1997 1922 2027 1923 2057 1924 2087 1925 2118 1926 2150 1927 2182 1928 2215 1929 2247 1930 2281 1931 2315 1932 2349 1933 2384 1934 2420 1935 2456 1936 2493 1937 2530 1938 2567 1939 2606 1940 2644 1941 2684 1942 2724 1943 2764 1944 2805 1945 2847 1946 2890 1947 2933 1948 2976 1949 3021 1950 3066 1951 3221 1952 3384 1953 3556 1954 3736 1955 3925 1956 4124 1957 4333 1958 4553 1959 4783 1960 5026 1961 5396 1962 5861 1963 5539 1964 5791 1965 6430 1966 6667 1967 7358 1968 7848 1969 8412 1970 9175 1971 9272 1972 9309 1973 9438 1974 10650 1975 10380 1976 10780 1977 11160 1978 11690 1979 12570 1980 13090 1981 12760 1982 12030 1983 11980 1984 12280 1985 12300 1986 12810 1987 13020 1988 13360 1989 13720 1990 13180 1991 12560 1992 11590 1993 11620 1994 12030 1995 12290 1996 12620 1997 13130 1998 13890 1999 13900 2000 14150 2001 13730 2002 13740 2003 13960 2004 14420 2005 14960 2006 15780 2007 16000 2008 16020 2009 15330 2010 15330 2011 15370 2012 15340 2013 15190 2014 14970 2015 15070 2016 15270 2017 15510 2018 15830 2019 16160