Year	Measure
1800	350
1820	350
1885	423.2
1886	405.7
1887	473
1888	453.7
1889	420.7
1890	417.8
1891	381.6
1892	416.6
1893	470.7
1894	533.7
1895	492.5
1896	540.9
1897	530.3
1898	542.9
1899	574.4
1900	560.5
1901	572.8
1902	620.7
1903	576.3
1904	635.5
1905	560.9
1906	534.5
1907	512.2
1908	557.7
1909	577.4
1910	614.4
1911	566
1912	609.8
1913	638.8
1914	608.3
1915	624.3
1916	620
1917	535.7
1918	462.9
1919	400
1920	376.8
1921	355
1922	382
1923	411.1
1924	442.4
1925	476
1926	512.2
1927	551.2
1928	593.1
1929	598.3
1930	623.6
1931	627.4
1932	616
1933	637.4
1934	693.9
1935	791.1
1936	842.5
1937	909.9
1938	904.7
1939	938.7
1940	897.1
1946	787.1
1947	872.1
1948	982.5
1949	1070
1950	1156
1951	1138
1952	1188
1953	1215
1954	1249
1955	1329
1956	1426
1957	1426
1958	1502
1959	1455
1960	1560
1961	1620
1962	1637
1963	1576
1964	1755
1965	1832
1966	1899
1967	1962
1968	2057
1969	2066
1970	2204
1971	2241
1972	2231
1973	2396
1974	2397
1975	2338
1976	2381
1977	2371
1978	2365
1979	2291
1980	2234
1981	2195
1982	2190
1983	2199
1984	2166
1985	2127
1986	2155
1987	2124
1988	2113
1989	2095
1990	1993
1991	1935
1992	1683
1993	1611
1994	1500
1995	1461
1996	1462
1997	1513
1998	1555
1999	1598
2000	1635
2001	1682
2002	1724
2003	1771
2004	1877
2005	1975
2006	2095
2007	2260
2008	2429
2009	2584
2010	2754
2011	2921
2012	3117
2013	3296
2014	3469
2015	3633
2016	3805
2017	3967
2018	4136