Year	Measure
1800	573.3
1820	573.3
1913	775
1950	969.6
1960	1120
1961	1168
1962	1220
1963	1246
1964	1326
1965	1433
1966	1484
1967	1512
1968	1544
1969	1634
1970	1771
1971	1840
1972	1899
1973	1976
1974	1981
1975	1920
1976	1815
1977	1791
1978	1903
1979	1896
1980	1810
1981	1761
1982	1723
1983	1732
1984	1682
1985	1704
1986	1739
1987	1742
1988	1748
1989	1680
1990	1588
1991	1696
1992	1881
1993	2166
1994	2235
1995	2104
1996	2207
1997	2064
1998	1933
1999	1918
2000	1822
2001	1774
2002	1727
2003	1722
2004	1729
2005	1747
2006	1746
2007	1828
2008	1905
2009	1976
2010	2074
2011	2247
2012	2392
2013	2437
2014	2510
2015	2940
2016	2975
2017	3013
2018	3024