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	0.4
1982	0.5
1983	0.5
1984	0.5
1985	0.5
1986	0.6
1987	0.6
1988	0.6
1989	0.7
1990	0.7
1991	0.7
1992	0.8
1993	0.8
1994	0.9
1995	0.9
1996	1
1997	1
1998	1
1999	1.1
2000	1.1
2001	1.2
2002	1.3
2003	1.3
2004	1.4
2005	1.4
2006	1.5
2007	1.6
2008	1.6
2009	1.7