Year Measure
1800 340
1820 340
1821 341.4
1822 342.8
1823 344.2
1824 345.6
1825 347.1
1826 348.5
1827 349.9
1828 351.4
1829 352.8
1830 354.3
1831 355.7
1832 357.2
1833 358.6
1834 360.1
1835 361.6
1836 363.1
1837 364.6
1838 366.1
1839 367.6
1840 369.1
1841 370.6
1842 372.2
1843 373.7
1844 375.2
1845 376.8
1846 378.3
1847 379.9
1848 381.4
1849 383
1850 384.6
1851 386.2
1852 387.8
1853 389.4
1854 391
1855 392.6
1856 394.2
1857 395.8
1858 397.4
1859 399.1
1860 400.7
1861 402.4
1862 404
1863 405.7
1864 407.4
1865 409
1866 410.7
1867 412.4
1868 414.1
1869 415.8
1870 417.5
1871 419.2
1872 421
1873 422.7
1874 424.4
1875 426.2
1876 427.9
1877 429.7
1878 431.5
1879 433.2
1880 435
1881 436.8
1882 438.6
1883 440.4
1884 442.2
1885 444
1886 445.9
1887 447.7
1888 449.6
1889 451.4
1890 453.3
1891 455.1
1892 457
1893 458.9
1894 460.8
1895 462.7
1896 464.6
1897 466.5
1898 468.4
1899 470.3
1900 472.3
1901 474.2
1902 476.2
1903 478.1
1904 480.1
1905 482.1
1906 484
1907 486
1908 488
1909 490.1
1910 492.1
1911 494.1
1912 496.1
1913 498.2
1914 500.2
1915 502.3
1916 504.3
1917 506.4
1918 508.5
1919 510.6
1920 512.7
1921 514.8
1922 516.9
1923 519.1
1924 521.2
1925 523.3
1926 525.5
1927 527.7
1928 529.8
1929 532
1930 534.2
1931 536.4
1932 538.6
1933 540.8
1934 543
1935 545.3
1936 547.5
1937 549.8
1938 552
1939 554.3
1940 556.6
1941 558.9
1942 561.2
1943 563.5
1944 565.8
1945 568.1
1946 570.5
1947 572.8
1948 575.2
1949 577.6
1950 579.9
1951 587.3
1952 594.7
1953 602.3
1954 593.9
1955 596.8
1956 604.3
1957 583.6
1958 578.7
1959 627.1
1960 654.6
1961 676.7
1962 695.8
1963 712.8
1964 727.6
1965 741.2
1966 754.2
1967 765.8
1968 776.9
1969 787.7
1970 798.3
1971 730.5
1972 691.5
1973 682.1
1974 660.1
1975 676.8
1976 671.1
1977 667.8
1978 730.7
1979 801.8
1980 1084
1981 1166
1982 1181
1983 1274
1984 1302
1985 1392
1986 1408
1987 1481
1988 1501
1989 1555
1990 1588
1993 1525
1994 1600
1995 1700
1996 1789
1997 1903
1998 2019
1999 2169
2000 2291
2001 2407
2002 2505
2003 2601
2004 2693
2005 2831
2006 3072
2007 3289
2008 3445
2009 3523
2010 3656
2011 3788
2012 3896
2013 4001
2014 4125
2015 4260
2016 4412
2017 4570
2018 4734