Year	Measure
1800	360
1820	360
1913	354.6
1950	352.5
1951	360.9
1952	369.2
1953	377.5
1954	385.8
1955	384.8
1956	408.5
1957	416.4
1958	422.2
1959	427.4
1960	428.7
1961	439.6
1962	427.9
1963	409.5
1964	390.2
1965	431.9
1966	463.4
1967	495.5
1968	476.6
1969	493.7
1970	488.7
1971	544.8
1972	584.6
1973	616.3
1974	638.8
1975	643.6
1976	649.7
1977	663.2
1978	703.6
1979	715.8
1980	700.1
1981	645.6
1982	632.8
1983	640.2
1984	649
1985	678.9
1986	656.8
1987	635.5
1988	610.9
1989	605.5
1990	602.7
1991	630.1
1992	563.2
1993	607.6
1994	555.4
1995	653.3
1996	685.1
1997	692.3
1998	696.5
1999	705.9
2000	713.8
2001	667.8
2002	665.4
2003	674.9
2004	691.8
2005	691
2006	685.8
2007	730.2
2008	769.4
2009	815.5
2010	844.4
2011	856.5
2012	848.2
2013	869.7
2014	896.5
2015	928.5
2016	963.3
2017	999
2018	1035