Year Measure
1820 1503
1821 1499
1822 1496
1823 1492
1824 1488
1825 1485
1826 1481
1827 1478
1828 1474
1829 1471
1830 1467
1831 1464
1832 1460
1833 1457
1834 1453
1835 1450
1836 1447
1837 1443
1838 1440
1839 1436
1840 1433
1841 1429
1842 1426
1843 1423
1844 1419
1845 1416
1846 1413
1847 1409
1848 1406
1849 1403
1850 1399
1851 1396
1852 1393
1853 1389
1854 1386
1855 1383
1856 1379
1857 1376
1858 1373
1859 1370
1860 1366
1861 1363
1862 1360
1863 1357
1864 1353
1865 1350
1866 1347
1867 1344
1868 1341
1869 1337
1870 1334
1871 1362
1872 1390
1873 1418
1874 1447
1875 1477
1876 1507
1877 1538
1878 1569
1879 1601
1880 1634
1881 1668
1882 1702
1883 1737
1884 1772
1885 1809
1886 1846
1887 1884
1888 1922
1889 1962
1890 2002
1891 2047
1892 2094
1893 2142
1894 2191
1895 2241
1896 2277
1897 2396
1898 2498
1899 2340
1900 2323
1901 2497
1902 2292
1903 2524
1904 2541
1905 2777
1906 2716
1907 2846
1908 2810
1909 2862
1910 2857
1911 2742
1912 2719
1913 2555
1914 2560
1915 2523
1916 2717
1917 2833
1918 2944
1919 3061
1920 3256
1921 3244
1922 3267
1923 3327
1924 3220
1925 3367
1926 3515
1927 3304
1928 3271
1929 3092
1930 2848
1931 2893
1932 2411
1933 2642
1934 2775
1935 2933
1936 3116
1937 3165
1938 3162
1939 3277
1940 3266
1941 3494
1942 3594
1943 3628
1944 3824
1945 3839
1946 3985
1947 4013
1948 4067
1949 4178
1950 4477
1951 4685
1952 4727
1953 4595
1954 4913
1955 5179
1956 5373
1957 5615
1958 5741
1959 5736
1960 6025
1961 6132
1962 6227
1963 6529
1964 7086
1965 7319
1966 7590
1967 7821
1968 8204
1969 8457
1970 8767
1971 8816
1972 9255
1973 9691
1974 9951
1975 10220
1976 10370
1977 10430
1978 11090
1979 11870
1980 12670
1981 13440
1982 13060
1983 12320
1984 12470
1985 12480
1986 11840
1987 11810
1988 11730
1989 11980
1990 12370
1991 12660
1992 12870
1993 12890
1994 13230
1995 12170
1996 12610
1997 13270
1998 13740
1999 14080
2000 14810
2001 14630
2002 14600
2003 14650
2004 15110
2005 15380
2006 15960
2007 16210
2008 16130
2009 14920
2010 15480
2011 15890
2012 16310
2013 16300
2014 16620
2015 17030
2016 17500
2017 17970
2018 18460
2019 18970