Year	Measure
1800	369
1820	369
1913	438.9
1950	470.3
1951	487.8
1952	493.3
1953	502.1
1954	519.6
1955	524.7
1956	532.8
1957	540.3
1958	542.9
1959	560.7
1960	564.2
1961	537.5
1962	597.5
1963	525.4
1964	451.9
1965	471.6
1966	490.6
1967	511
1968	531.6
1969	572.6
1970	616.4
1971	605.8
1972	590.6
1973	591.3
1974	602.1
1975	692.8
1976	659
1977	670.1
1978	711.1
1979	753.5
1980	818.7
1981	843.7
1982	881.6
1983	902.6
1984	840.8
1985	856
1986	879.9
1987	848
1988	793.6
1989	786.3
1990	760.7
1991	708.9
1992	737.1
1993	660.8
1994	382.4
1995	581.4
1996	622.9
1997	589.9
1998	643.7
1999	677.5
2000	704
2001	735
2002	785.7
2003	774.1
2004	785.8
2005	813
2006	872.3
2007	901.5
2008	1001
2009	1042
2010	1094
2011	1160
2012	1224
2013	1289
2014	1354
2015	1419
2016	1487
2017	1558
2018	1625