Year	Measure
1800	484.7
1820	484.7
1913	749
1950	1552
1951	1582
1952	1616
1953	1647
1954	1680
1955	1714
1956	1845
1957	1770
1958	1794
1959	1952
1960	1935
1961	1883
1962	1960
1963	1852
1964	1785
1965	1861
1966	1790
1967	1688
1968	1744
1969	1803
1970	1679
1971	1745
1972	1660
1973	1474
1974	1574
1975	1720
1976	1974
1977	2203
1978	2094
1979	1808
1980	1761
1981	1740
1982	1896
1983	1812
1984	1661
1985	1496
1986	1509
1987	1508
1988	1494
1989	1574
1990	1405
1991	1459
1992	1492
1993	1495
1994	1484
1995	1488
1996	1524
1997	1632
1998	1681
1999	1758
2000	1874
2001	1933
2002	1993
2003	2078
2004	2126
2005	2249
2006	2387
2007	2525
2008	2535
2009	2599
2010	2597
2011	3131
2012	2918
2013	2877
2014	2875
2015	2921
2016	2931
2017	2959
2018	3000