Year	Measure
1800	509.2
1820	539
1850	571.9
1851	611.4
1852	594.9
1853	558.2
1854	539.2
1855	544.3
1856	564.1
1857	603.6
1858	642.5
1859	637.3
1860	654.2
1861	648.3
1862	617.6
1863	631.5
1864	640.3
1865	687.9
1866	712.8
1867	772.1
1868	772.1
1869	772.1
1870	715.7
1871	715.7
1872	740.6
1873	718.7
1874	729.6
1875	740.6
1876	712.8
1877	693
1878	726.7
1879	732.6
1880	698.9
1881	704.7
1882	721.6
1883	701.8
1884	749.4
1885	696
1886	718.7
1887	671
1888	645.4
1889	654.2
1890	715.7
1891	760.4
1892	659.3
1893	561.2
1894	561.2
1895	665.2
1896	603.6
1897	594.9
1898	608.8
1899	597.8
1900	575.1
1901	648.5
1902	629.7
1903	631
1904	622.6
1905	632.6
1906	697
1907	691.3
1908	654.7
1909	705.5
1910	711.4
1911	737.7
1912	770.7
1913	778.2
1914	750.1
1915	738.1
1916	729.7
1917	783.7
1918	749
1919	792.6
1920	875.5
1921	874.1
1922	925.6
1923	984.1
1924	980.1
1925	960
1926	989.1
1927	1076
1928	1178
1929	1165
1930	1118
1931	1057
1932	1081
1933	1157
1934	1237
1935	1250
1936	1375
1937	1410
1938	1444
1939	1450
1940	1406
1941	1444
1942	1370
1943	1457
1944	1539
1945	1554
1946	1695
1947	1694
1948	1814
1949	1904
1950	1980
1951	2020
1952	2109
1953	2146
1954	2249
1955	2379
1956	2377
1957	2487
1958	2680
1959	2862
1960	3044
1961	3214
1962	3337
1963	3260
1964	3277
1965	3261
1966	3385
1967	3430
1968	3667
1969	3909
1970	4184
1971	4555
1972	4986
1973	5559
1974	5874
1975	6032
1976	6501
1977	6660
1978	6826
1979	7118
1980	7623
1981	7129
1982	7031
1983	6672
1984	6890
1985	7287
1986	7685
1987	7807
1988	7657
1989	7763
1990	7137
1991	7098
1992	6950
1993	7188
1994	7504
1995	7713
1996	7810
1997	7958
1998	7861
1999	7819
2000	8056
2001	8023
2002	8131
2003	8110
2004	8461
2005	8596
2006	8842
2007	9290
2008	9682
2009	9565
2010	10200
2011	10380
2012	10380
2013	10620
2014	10960
2015	11330
2016	11720
2017	12130
2018	12560