Year	Measure
1800	697.3
1820	697.3
1896	842.2
1897	909.3
1898	956
1899	996.5
1900	1036
1901	1098
1902	1144
1903	1206
1904	1231
1905	1305
1906	1392
1907	1460
1908	1469
1909	1476
1910	1482
1911	1495
1912	1528
1913	1560
1914	1531
1915	1642
1916	1790
1917	1833
1918	1821
1919	1858
1920	1853
1921	1900
1922	2032
1923	2138
1924	2303
1925	2327
1926	2524
1927	2529
1928	2651
1929	2882
1930	2513
1931	2273
1932	2150
1933	2354
1934	2630
1935	2830
1936	2918
1937	2910
1938	2909
1939	2878
1940	2887
1941	2841
1942	2730
1943	2726
1944	2910
1945	2967
1946	3030
1947	3062
1948	3111
1949	3289
1950	3487
1951	3665
1952	3759
1953	3896
1954	3903
1955	4084
1956	4157
1957	4245
1958	4145
1959	4053
1960	4486
1961	4748
1962	4957
1963	5038
1964	5236
1965	5431
1966	5724
1967	5788
1968	5569
1969	5555
1970	5824
1971	5917
1972	5938
1973	6079
1974	6224
1975	6537
1976	6453
1977	6281
1978	6118
1979	6317
1980	6441
1981	6561
1982	6435
1983	5453
1984	5578
1985	5563
1986	5988
1987	6361
1988	5715
1989	4911
1990	4564
1991	4581
1992	4446
1993	4603
1994	5123
1995	5454
1996	5474
1997	5838
1998	5745
1999	5705
2000	5791
2001	5715
2002	5909
2003	6055
2004	6161
2005	6466
2006	6860
2007	7318
2008	7913
2009	7859
2010	8420
2011	8865
2012	9278
2013	9710
2014	10150
2015	10590
2016	11060
2017	11540
2018	12050