Year	Measure
1800	442
1820	442
1870	547.5
1883	794.3
1884	815.5
1885	862
1886	806.9
1887	886.7
1888	908.9
1889	873.1
1890	919.5
1891	821.9
1892	703.1
1893	975.2
1894	827.8
1895	947.7
1896	834.8
1897	755.7
1898	843.3
1899	827.5
1900	789.8
1901	766.2
1902	823.7
1903	879.5
1904	843
1905	828.1
1906	768.6
1907	762.1
1908	809.5
1909	832.3
1910	851.8
1911	902.6
1912	926.2
1913	1064
1914	920.7
1915	942.8
1916	886.4
1917	1030
1918	1018
1919	946.3
1920	1130
1921	1122
1922	1164
1923	1340
1924	1600
1925	2055
1926	2451
1927	2590
1928	2940
1929	3252
1930	3258
1931	2722
1932	2801
1933	2731
1934	2884
1935	3179
1936	3285
1937	3621
1938	3769
1939	3938
1940	3734
1941	3706
1942	3330
1943	3495
1944	4324
1945	4995
1946	5771
1947	6851
1948	7911
1949	7732
1950	7375
1951	7512
1952	7690
1953	7730
1954	8115
1955	8388
1956	8993
1957	9802
1958	9065
1959	9032
1960	8714
1961	8309
1962	8423
1963	8357
1964	9244
1965	9425
1966	9260
1967	9541
1968	9904
1969	9898
1970	10330
1971	10430
1972	10510
1973	10970
1974	11420
1975	11860
1976	12690
1977	13140
1978	13040
1979	12810
1980	12120
1981	11730
1982	11150
1983	10040
1984	9501
1985	9269
1986	9412
1987	9884
1988	10350
1989	9427
1990	9701
1991	10240
1992	10730
1993	10530
1994	9912
1995	9935
1996	9726
1997	10170
1998	10010
1999	9245
2000	9434
2001	9605
2002	8605
2003	7811
2004	9121
2005	9876
2006	10710
2007	11450
2008	11860
2009	11300
2010	10960
2011	11240
2012	11690
2013	11510
2014	11590
2015	11670
2016	11770
2017	11880
2018	12000