Year	Years
1970	0.1
1971	0.1
1972	0.1
1973	0.1
1974	0.2
1975	0.2
1976	0.2
1977	0.2
1978	0.2
1979	0.2
1980	0.2
1981	0.2
1982	0.2
1983	0.3
1984	0.3
1985	0.3
1986	0.3
1987	0.3
1988	0.3
1989	0.4
1990	0.4
1991	0.4
1992	0.4
1993	0.4
1994	0.5
1995	0.5
1996	0.5
1997	0.5
1998	0.5
1999	0.6
2000	0.6
2001	0.6
2002	0.6
2003	0.7
2004	0.7
2005	0.7
2006	0.8
2007	0.8
2008	0.8
2009	0.8