Year	Years
1800	467.2
1950	159.8
1951	157.1
1952	153
1953	148.1
1954	143.7
1955	138.6
1956	134
1957	128.7
1958	124
1959	119.4
1960	114.3
1967	108.5
1968	104.2
1969	100.2
1970	96.2
1971	92.5
1972	88.8
1973	85.4
1974	82.1
1975	79.2
1976	76.3
1977	73.6
1978	71
1979	68.4
1980	65.9
1981	63.4
1982	60.9
1983	58.4
1984	55.7
1985	53
1986	50.3
1987	47.5
1988	44.8
1989	42.1
1990	39.6
1991	37.2
1992	35.1
1993	33.2
1994	31.6
1995	30.2
1996	29
1997	27.9
1998	26.9
1999	26
2000	25.1
2001	24.3
2002	23.5
2003	22.8
2004	22.2
2005	21.5
2006	20.9
2007	20.2
2008	19.6
2009	18.9
2010	18.3
2011	17.7
2012	17.2
2013	16.7