Year Measure
1820 898.3
1821 908.8
1822 919.5
1823 930.3
1824 941.2
1825 952.3
1826 963.5
1827 974.8
1828 986.2
1829 997.8
1830 1010
1831 1021
1832 1033
1833 1045
1834 1058
1835 1070
1836 1083
1837 1095
1838 1108
1839 1121
1840 1134
1841 1148
1842 1161
1843 1175
1844 1189
1845 1203
1846 1217
1847 1231
1848 1245
1849 1260
1850 1275
1851 1290
1852 1305
1853 1320
1854 1336
1855 1352
1856 1367
1857 1383
1858 1400
1859 1416
1860 1433
1861 1450
1862 1467
1863 1484
1864 1501
1865 1519
1866 1537
1867 1555
1868 1573
1869 1591
1870 1610
1871 1629
1872 1648
1873 1667
1874 1687
1875 1707
1876 1727
1877 1747
1878 1768
1879 1788
1880 1809
1881 1831
1882 1852
1883 1874
1884 1896
1885 1918
1886 1941
1887 1963
1888 1986
1889 2010
1890 2033
1891 2057
1892 2081
1893 2106
1894 2131
1895 2156
1896 2181
1897 2206
1898 2232
1899 2259
1900 2285
1901 2312
1902 2339
1903 2367
1904 2394
1905 2422
1906 2451
1907 2480
1908 2509
1909 2538
1910 2568
1911 2598
1912 2629
1913 2659
1914 2683
1915 2707
1916 2731
1917 2756
1918 2780
1919 2805
1920 2830
1921 2855
1922 2881
1923 2906
1924 2932
1925 2958
1926 2985
1927 3011
1928 3038
1929 3065
1930 3092
1931 3120
1932 3148
1933 3176
1934 3204
1935 3233
1936 3262
1937 3291
1938 3320
1939 3349
1940 3379
1941 3409
1942 3440
1943 3470
1944 3501
1945 3533
1946 3564
1947 3596
1948 3628
1949 3660
1950 3693
1951 3838
1952 3989
1953 4147
1954 4310
1955 4479
1956 4656
1957 4839
1958 5030
1959 5228
1960 5434
1961 5648
1962 5870
1963 6101
1964 6342
1965 6591
1966 6851
1967 7121
1968 7401
1969 7692
1970 7995
1971 9010
1972 9640
1973 9919
1974 9721
1975 8160
1976 9711
1977 11250
1978 12060
1979 13160
1980 13790
1981 14030
1982 14750
1983 15330
1984 16460
1985 17030
1986 17470
1987 18500
1988 19820
1989 21120
1990 22220
1991 21790
1992 23220
1993 22810
1994 23640
1995 25510
1996 25580
1997 25800
1998 26770
1999 27760
2000 28850
2001 29670
2002 29940
2003 30050
2004 30610
2005 30940
2006 31630
2007 32450
2008 32750
2009 31270
2010 30900
2011 30260
2012 29200
2013 27140
2014 25580
2015 25530
2016 25750
2017 26110
2018 26460
2019 26750