Year	Measure
1800	453.6
1820	453.6
1850	465.1
1870	702.3
1871	682.2
1872	647.3
1873	650.3
1874	639.1
1875	643.9
1876	650.6
1877	654.2
1878	592
1879	634.8
1880	685.1
1881	731.4
1882	771.5
1883	776.6
1884	746.2
1885	694.8
1886	668.4
1887	779.6
1888	759.9
1889	743.7
1890	862.2
1891	855.2
1892	867.9
1893	868.2
1894	860.6
1895	895
1896	897.5
1897	928
1898	963.3
1899	1018
1900	1064
1901	983.1
1902	969.6
1903	1011
1904	1002
1905	972.5
1906	982
1907	1017
1908	1007
1909	951
1910	996.5
1911	957
1912	954.1
1913	1018
1914	998
1915	937.4
1916	967.3
1917	1004
1918	913.5
1919	962.2
1920	900.8
1921	873.6
1922	896.2
1923	879
1924	930.2
1925	979.1
1926	1045
1927	1041
1928	1037
1929	1102
1930	1044
1931	992.2
1932	941.2
1933	948.7
1934	1039
1935	976.7
1936	969
1937	1028
1938	1011
1939	978.5
1940	1032
1941	1053
1942	1091
1943	1059
1944	952.3
1945	920.4
1946	866.4
1947	885.5
1948	956.2
1949	989.1
1950	1033
1951	1067
1952	1084
1953	1072
1954	1071
1955	1105
1956	1084
1957	1073
1958	1076
1959	1063
1960	1072
1961	1065
1962	1074
1963	1070
1964	1094
1965	1102
1966	1065
1967	1136
1968	1192
1969	1213
1970	1245
1971	1211
1972	1213
1973	1241
1974	1262
1975	1271
1976	1287
1977	1349
1978	1408
1979	1471
1980	1525
1981	1595
1982	1648
1983	1709
1984	1771
1985	1822
1986	1886
1987	1877
1988	1899
1989	1922
1990	2019
1991	2088
1992	2154
1993	2272
1994	2366
1995	2465
1996	2530
1997	2664
1998	2762
1999	2854
2000	2998
2001	2926
2002	3015
2003	3167
2004	3310
2005	3481
2006	3719
2007	3941
2008	4143
2009	4256
2010	4561
2011	4904
2012	5183
2013	5469
2014	5799
2015	6134
2016	6488
2017	6863
2018	7260