Year	Years
1800	435.2
1900	434.2
1930	407.1
1950	230.2
1951	228.7
1952	226.4
1953	222.9
1954	220
1955	216
1956	211
1957	205.7
1958	200.3
1959	195
1960	189
1961	182.3
1962	176.5
1963	170
1964	163
1965	156.8
1975	107.4
1976	100.9
1977	94.8
1978	89.1
1979	83.7
1980	78.7
1981	73.9
1982	69.5
1983	65.3
1984	61.4
1985	57.8
1986	54.4
1987	51.2
1988	48.3
1989	45.7
1990	43.4
1991	41.3
1992	39.5
1993	37.9
1994	36.5
1995	35.2
1996	34
1997	32.9
1998	31.9
1999	31
2000	30.2
2001	29.5
2002	28.8
2003	28.2
2004	27.5
2005	26.9
2006	26.3
2007	25.7
2008	25.1
2009	24.5
2010	23.8
2011	23.1
2012	22.5
2013	21.8