Year	Measure
1800	633.5
1820	646.9
1885	975
1886	937.4
1887	1096
1888	1054
1889	980.4
1890	976.4
1891	894.3
1892	979.1
1893	1110
1894	1261
1895	1167
1896	1286
1897	1264
1898	1298
1899	1377
1900	1348
1901	1381
1902	1501
1903	1397
1904	1545
1905	1368
1906	1307
1907	1256
1908	1372
1909	1424
1910	1520
1911	1404
1912	1517
1913	1594
1914	1522
1915	1566
1916	1393
1917	1223
1918	748.5
1919	645.3
1920	647.9
1921	593.1
1922	688.4
1923	792.9
1924	1005
1925	1255
1926	1409
1927	1468
1928	1544
1929	1562
1930	1633
1931	1647
1932	1622
1933	1683
1934	1837
1935	2101
1936	2244
1937	2430
1938	2423
1939	2521
1940	2416
1946	2156
1947	2396
1948	2707
1949	2957
1950	3203
1951	3162
1952	3310
1953	3395
1954	3501
1955	3734
1956	4020
1957	4030
1958	4257
1959	4135
1960	4447
1961	4619
1962	4666
1963	4492
1964	5003
1965	5223
1966	5414
1967	5594
1968	5863
1969	5889
1970	6284
1971	6387
1972	6360
1973	6829
1974	6793
1975	6585
1976	6666
1977	6598
1978	6543
1979	6301
1980	6107
1981	5965
1982	5914
1983	5905
1984	5782
1985	5642
1986	5682
1987	5568
1988	5505
1989	5425
1990	5132
1991	4770
1992	3962
1993	3934
1994	3185
1995	2895
1996	3029
1997	2631
1998	2764
1999	3160
2000	3290
2001	3361
2002	3359
2003	3523
2004	3968
2005	4247
2006	4639
2007	5070
2008	5726
2009	5982
2010	6427
2011	7253
2012	7921
2013	8398
2014	8921
2015	9437
2016	10030
2017	10650
2018	11240