Year	Years
1800	473.6
1950	140.1
1951	137.6
1952	133.8
1953	129.8
1954	125.7
1955	121.6
1956	118
1957	113.7
1958	109.3
1959	105
1960	101.4
1961	97.33
1962	93.88
1963	90.52
1964	87.2
1965	84.46
1966	81.24
1967	78.05
1968	75.54
1969	72.68
1970	70.43
1971	68.32
1972	65.87
1973	63.99
1974	62.14
1975	60.31
1976	58.48
1977	56.67
1978	55.31
1979	53.55
1980	51.8
1990	25.5
1991	24.2
1992	23
1993	21.9
1994	20.8
1995	19.8
1996	18.8
1997	17.9
1998	17
1999	16.2
2000	15.4
2001	14.7
2002	14.1
2003	13.5
2004	12.9
2005	12.4
2006	11.9
2007	11.4
2008	11
2009	10.6
2010	10.3
2011	9.9
2012	9.6
2013	9.3