Year	Measure
1800	836.3
1820	853.9
1870	1084
1890	1460
1900	1579
1910	1880
1913	1980
1924	1173
1925	1191
1926	1510
1927	1620
1928	1574
1929	1524
1930	1658
1931	1877
1932	1864
1933	1871
1934	1690
1935	1596
1936	1928
1937	2022
1938	2059
1939	2069
1940	1999
1941	2023
1942	1910
1943	1954
1944	1791
1945	1385
1950	2132
1951	2567
1952	2444
1953	2692
1954	2614
1955	2773
1956	2747
1957	3009
1958	3238
1959	3465
1960	3759
1961	3966
1962	4254
1963	4413
1964	4722
1965	4970
1966	5326
1967	5577
1968	5639
1969	5869
1970	6162
1971	6329
1972	6597
1973	6822
1974	6990
1975	7528
1976	7723
1977	7612
1978	7771
1979	8063
1980	7803
1981	7987
1982	8224
1983	8052
1984	8302
1985	8038
1986	8236
1987	8240
1988	8179
1989	8025
1990	7226
1991	6711
1992	6303
1993	6367
1994	6551
1995	6820
1996	6251
1997	5970
1998	6283
1999	6491
2000	6907
2001	7265
2002	7697
2003	8105
2004	8721
2005	9353
2006	10010
2007	10710
2008	11430
2009	10860
2010	10990
2011	11460
2012	11670
2013	11930
2014	12260
2015	12690
2016	13140
2017	13600
2018	14070