Year	Measure
1800	467.3
1820	467.3
1885	658.5
1886	632.4
1887	738.7
1888	709.9
1889	659.4
1890	656
1891	600.3
1892	656.5
1893	743.2
1894	844.1
1895	780.3
1896	858.5
1897	843.2
1898	864.8
1899	916.7
1900	896.1
1901	917.5
1902	996
1903	926.3
1904	1023
1905	904.8
1906	863.9
1907	829.2
1908	904.6
1909	938.3
1910	1000
1911	923.1
1912	996.3
1913	1046
1914	997.4
1915	1025
1916	910.7
1917	798.8
1918	488.5
1919	420.7
1920	422
1921	385.9
1922	447.5
1923	514.8
1924	651.6
1925	813.4
1926	912.3
1927	949.4
1928	997.4
1929	1008
1930	1052
1931	1061
1932	1043
1933	1081
1934	1179
1935	1347
1936	1437
1937	1555
1938	1549
1939	1610
1940	1541
1946	1367
1947	1518
1948	1713
1949	1869
1950	2022
1951	1995
1952	2086
1953	2137
1954	2201
1955	2345
1956	2522
1957	2526
1958	2666
1959	2587
1960	2779
1961	2886
1962	2916
1963	2807
1964	3126
1965	3264
1966	3383
1967	3495
1968	3664
1969	3680
1970	3927
1971	3991
1972	3974
1973	4268
1974	4352
1975	4326
1976	4489
1977	4557
1978	4633
1979	4574
1980	4545
1981	4552
1982	4627
1983	4737
1984	4756
1985	4758
1986	4913
1987	4936
1988	5004
1989	5056
1990	4904
1991	4018
1992	2840
1993	2799
1994	1932
1995	1907
1996	1798
1997	1830
1998	1714
1999	1657
2000	1692
2001	1795
2002	1934
2003	2053
2004	2202
2005	2362
2006	2482
2007	2563
2008	2769
2009	2607
2010	2795
2011	2988
2012	2964
2013	3085
2014	3212
2015	3375
2016	3547
2017	3728
2018	3918