Year	Years
1800	396.8
1900	329.5
1930	221.5
1950	135.9
1951	133.4
1952	130.3
1953	126.4
1954	123
1955	119.6
1956	116
1957	112.4
1958	108.7
1959	105.6
1960	102
1961	98.51
1971	63.8
1972	61.9
1973	59.9
1974	58.1
1975	56.3
1976	54.7
1977	52.9
1978	51.4
1979	49.9
1980	48.5
1981	46.9
1982	45.1
1983	43.2
1984	41.2
1985	39
1986	36.9
1987	35.2
1988	33.7
1989	32.7
1990	32.3
1991	32.5
1992	33.3
1993	34.5
1994	35.5
1995	36.2
1996	36.2
1997	35.5
1998	34.2
1999	32.4
2000	30.6
2001	28.6
2002	26.7
2003	25
2004	23.5
2005	22.2
2006	21.1
2007	20
2008	19
2009	18.1
2010	17.4
2011	16.7
2012	16
2013	15.4