Year	Years
1800	463.4
1950	408.9
1951	405.4
1952	400.7
1953	394.3
1954	387.5
1955	381.4
1956	373.8
1957	365.8
1958	357.4
1968	288.7
1969	280.9
1970	273.1
1971	265.6
1972	258.3
1973	250.9
1974	243.7
1975	236.5
1976	229.5
1977	222.2
1978	214.9
1979	207.7
1980	200.3
1981	193
1982	185.9
1983	178.9
1984	172
1985	165.4
1986	158.8
1987	152.3
1988	146
1989	139.7
1990	133.7
1991	127.7
1992	121.8
1993	116.1
1994	110.5
1995	104.9
1996	99.5
1997	94.2
1998	89
1999	84.1
2000	79.4
2001	74.9
2002	70.6
2003	66.3
2004	62.4
2005	58.5
2006	54.9
2007	51.5
2008	48.2
2009	45.2
2010	42.5
2011	40.1
2012	38
2013	36.2