Year Measure 1820 718.4 1821 721.7 1822 725.1 1823 728.5 1824 731.9 1825 735.4 1826 738.8 1827 742.3 1828 745.7 1829 749.2 1830 752.8 1831 756.3 1832 759.8 1833 763.4 1834 767 1835 770.6 1836 774.2 1837 777.8 1838 781.5 1839 785.1 1840 788.8 1841 792.5 1842 796.2 1843 800 1844 803.7 1845 807.5 1846 811.3 1847 815.1 1848 818.9 1849 822.7 1850 826.6 1851 830.5 1852 834.4 1853 838.3 1854 842.2 1855 846.1 1856 850.1 1857 854.1 1858 858.1 1859 862.1 1860 866.2 1861 870.2 1862 874.3 1863 878.4 1864 882.5 1865 886.7 1866 890.8 1867 895 1868 899.2 1869 903.4 1870 907.7 1871 911.9 1872 916.2 1873 920.5 1874 924.8 1875 929.1 1876 933.5 1877 937.9 1878 942.3 1879 946.7 1880 951.1 1881 955.6 1882 960.1 1883 964.6 1884 969.1 1885 973.6 1886 978.2 1887 982.8 1888 987.4 1889 992 1890 996.7 1891 1001 1892 1006 1893 1011 1894 1016 1895 1020 1896 1025 1897 1030 1898 1035 1899 1040 1900 1044 1901 1049 1902 1054 1903 1059 1904 1064 1905 1069 1906 1074 1907 1079 1908 1084 1909 1089 1910 1094 1911 1100 1912 1105 1913 1110 1914 1110 1915 1110 1916 1110 1917 1111 1918 1111 1919 1111 1920 1111 1921 1111 1922 1111 1923 1112 1924 1112 1925 1112 1926 1112 1927 1112 1928 1112 1929 1113 1930 1113 1931 1113 1932 1113 1933 1113 1934 1113 1935 1114 1936 1114 1937 1114 1938 1114 1939 1114 1940 1114 1941 1114 1942 1115 1943 1115 1944 1115 1945 1115 1946 1115 1947 1115 1948 1116 1949 1116 1950 1116 1951 1135 1952 1153 1953 1171 1954 1189 1955 1207 1956 1225 1957 1242 1958 1258 1959 1275 1960 1356 1961 1415 1962 1432 1963 1465 1964 1635 1965 1811 1966 1927 1967 1982 1968 2028 1969 2189 1970 2091 1971 2188 1972 2213 1973 2075 1974 2113 1975 2052 1976 1995 1977 2056 1978 2213 1979 2290 1980 2132 1981 1940 1982 1803 1983 1647 1984 1638 1985 1655 1986 1648 1987 1612 1988 1626 1989 1627 1990 1556 1991 1494 1992 1387 1993 1166 1994 1361 1995 1376 1996 1440 1997 1317 1998 1251 1999 1252 2000 1194 2001 1169 2002 1189 2003 1217 2004 1212 2005 1191 2006 1209 2007 1206 2008 1204 2009 1220 2010 1241 2011 1273 2012 1314 2013 1352 2014 1396 2015 1442 2016 1491 2017 1537 2018 1580 2019 1619