Year Measure
1820 1762
1821 1786
1822 1811
1823 1835
1824 1860
1825 1886
1826 1911
1827 1937
1828 1964
1829 1991
1830 2018
1831 2045
1832 2073
1833 2101
1834 2130
1835 2159
1836 2188
1837 2218
1838 2248
1839 2279
1840 2310
1841 2341
1842 2373
1843 2406
1844 2438
1845 2471
1846 2505
1847 2539
1848 2574
1849 2609
1850 2644
1851 2680
1852 2717
1853 2754
1854 2791
1855 2829
1856 2868
1857 2907
1858 2947
1859 2987
1860 3027
1861 3069
1862 3110
1863 3153
1864 3196
1865 3239
1866 3283
1867 3328
1868 3373
1869 3419
1870 3466
1871 3517
1872 3568
1873 3621
1874 3674
1875 3728
1876 3782
1877 3838
1878 3894
1879 3951
1880 4009
1881 4068
1882 4128
1883 4189
1884 4250
1885 4312
1886 4376
1887 4440
1888 4505
1889 4571
1890 4638
1891 4698
1892 4758
1893 4819
1894 4880
1895 4943
1896 5006
1897 5070
1898 5135
1899 5201
1900 5267
1901 5352
1902 5438
1903 5526
1904 5615
1905 5705
1906 5797
1907 5890
1908 5985
1909 6082
1910 6179
1911 6278
1912 6379
1913 6481
1914 6321
1915 6165
1916 6012
1917 5864
1918 5719
1919 5577
1920 5440
1921 5305
1922 5174
1923 5046
1924 4921
1925 4800
1926 4681
1927 4621
1928 4558
1929 4290
1930 4537
1931 4574
1932 4260
1933 4409
1934 4400
1935 4453
1936 4445
1937 4208
1938 4623
1939 4433
1940 4251
1941 4076
1942 3909
1943 3748
1944 3594
1945 3447
1946 3305
1947 3169
1948 3039
1949 3657
1950 4400
1951 4674
1952 4962
1953 5253
1954 5569
1955 5874
1956 6043
1957 6223
1958 6416
1959 6637
1960 6863
1961 7263
1962 7472
1963 7953
1964 8406
1965 8882
1966 9838
1967 10210
1968 10200
1969 10510
1970 10620
1971 11990
1972 12640
1973 12940
1974 13540
1975 14000
1976 14580
1977 14760
1978 15120
1979 15440
1980 15390
1981 15210
1982 15160
1983 14990
1984 15550
1985 15480
1986 15690
1987 15300
1988 15210
1989 14670
1990 13070
1991 11400
1992 10410
1993 10580
1994 11010
1995 11810
1996 12310
1997 11590
1998 11060
1999 10940
2000 11190
2001 11840
2002 12440
2003 13070
2004 14190
2005 14790
2006 15980
2007 17010
2008 18290
2009 17110
2010 16950
2011 17360
2012 17520
2013 18180
2014 18620
2015 19120
2016 19710
2017 20410
2018 21160
2019 21940