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