Year	Measure
1800	771.2
1820	787.4
1885	1187
1886	1141
1887	1334
1888	1283
1889	1193
1890	1189
1891	1089
1892	1192
1893	1351
1894	1536
1895	1421
1896	1565
1897	1539
1898	1580
1899	1676
1900	1640
1901	1681
1902	1827
1903	1701
1904	1881
1905	1665
1906	1591
1907	1529
1908	1670
1909	1734
1910	1850
1911	1709
1912	1847
1913	1940
1914	1852
1915	1907
1916	1695
1917	1488
1918	911.1
1919	785.5
1920	788.7
1921	721.9
1922	838
1923	965.2
1924	1223
1925	1528
1926	1716
1927	1787
1928	1879
1929	1901
1930	1987
1931	2005
1932	1974
1933	2049
1934	2237
1935	2557
1936	2731
1937	2958
1938	2949
1939	3069
1940	2941
1946	2625
1947	2917
1948	3295
1949	3599
1950	3898
1951	3850
1952	4029
1953	4133
1954	4262
1955	4545
1956	4893
1957	4906
1958	5182
1959	5034
1960	5413
1961	5622
1962	5680
1963	5468
1964	6090
1965	6357
1966	6591
1967	6809
1968	7137
1969	7169
1970	7649
1971	7775
1972	7742
1973	8313
1974	8520
1975	8510
1976	8876
1977	9053
1978	9250
1979	9179
1980	9166
1981	9224
1982	9424
1983	9696
1984	9781
1985	9835
1986	10200
1987	10300
1988	10500
1989	10660
1990	10390
1991	9409
1992	8246
1993	7733
1994	7734
1995	8199
1996	8680
1997	9690
1998	10280
1999	10360
2000	11240
2001	12050
2002	13010
2003	13770
2004	15010
2005	16650
2006	18370
2007	19780
2008	18980
2009	16320
2010	16870
2011	18260
2012	18860
2013	19420
2014	20040
2015	20710
2016	21440
2017	22210
2018	23040