Year	Years
1970	0.2
1971	0.2
1972	0.3
1973	0.3
1974	0.3
1975	0.3
1976	0.3
1977	0.3
1978	0.3
1979	0.4
1980	0.4
1981	0.4
1982	0.4
1983	0.5
1984	0.5
1985	0.5
1986	0.6
1987	0.6
1988	0.7
1989	0.8
1990	0.8
1991	0.9
1992	0.9
1993	1
1994	1.1
1995	1.1
1996	1.2
1997	1.3
1998	1.3
1999	1.4
2000	1.5
2001	1.6
2002	1.7
2003	1.8
2004	1.8
2005	1.9
2006	2
2007	2.1
2008	2.2
2009	2.3