Year Measure
1800 509.2
1820 539
1850 571.9
1851 611.4
1852 594.9
1853 558.2
1854 539.2
1855 544.3
1856 564.1
1857 603.6
1858 642.5
1859 637.3
1860 654.2
1861 648.3
1862 617.6
1863 631.5
1864 640.3
1865 687.9
1866 712.8
1867 772.1
1868 772.1
1869 772.1
1870 715.7
1871 715.7
1872 740.6
1873 718.7
1874 729.6
1875 740.6
1876 712.8
1877 693
1878 726.7
1879 732.6
1880 698.9
1881 704.7
1882 721.6
1883 701.8
1884 749.4
1885 696
1886 718.7
1887 671
1888 645.4
1889 654.2
1890 715.7
1891 760.4
1892 659.3
1893 561.2
1894 561.2
1895 665.2
1896 603.6
1897 594.9
1898 608.8
1899 597.8
1900 575.1
1901 648.5
1902 629.7
1903 631
1904 622.6
1905 632.6
1906 697
1907 691.3
1908 654.7
1909 705.5
1910 711.4
1911 737.7
1912 770.7
1913 778.2
1914 750.1
1915 738.1
1916 729.7
1917 783.7
1918 749
1919 792.6
1920 875.5
1921 874.1
1922 925.6
1923 984.1
1924 980.1
1925 960
1926 989.1
1927 1076
1928 1178
1929 1165
1930 1118
1931 1057
1932 1081
1933 1157
1934 1237
1935 1250
1936 1375
1937 1410
1938 1444
1939 1450
1940 1406
1941 1444
1942 1370
1943 1457
1944 1539
1945 1554
1946 1695
1947 1694
1948 1814
1949 1904
1950 1980
1951 2020
1952 2109
1953 2146
1954 2249
1955 2379
1956 2377
1957 2487
1958 2680
1959 2862
1960 3044
1961 3214
1962 3337
1963 3260
1964 3277
1965 3261
1966 3385
1967 3430
1968 3667
1969 3909
1970 4184
1971 4555
1972 4986
1973 5559
1974 5874
1975 6032
1976 6501
1977 6660
1978 6826
1979 7118
1980 7623
1981 7129
1982 7031
1983 6672
1984 6890
1985 7287
1986 7685
1987 7807
1988 7657
1989 7763
1990 7137
1991 7098
1992 6950
1993 7188
1994 7504
1995 7713
1996 7810
1997 7958
1998 7861
1999 7819
2000 8056
2001 8023
2002 8131
2003 8110
2004 8461
2005 8596
2006 8842
2007 9290
2008 9682
2009 9565
2010 10200
2011 10380
2012 10380
2013 10620
2014 10960
2015 11330
2016 11720
2017 12130
2018 12560