Year	Years
1970	0.3
1971	0.31
1972	0.32
1973	0.33
1974	0.34
1975	0.36
1976	0.37
1977	0.38
1978	0.4
1979	0.41
1980	0.43
1981	0.44
1982	0.46
1983	0.48
1984	0.5
1985	0.52
1986	0.53
1987	0.55
1988	0.58
1989	0.6
1990	0.62
1991	0.64
1992	0.67
1993	0.7
1994	0.72
1995	0.75
1996	0.78
1997	0.81
1998	0.84
1999	0.87
2000	0.91
2001	0.94
2002	0.97
2003	1.01
2004	1.04
2005	1.08
2006	1.12
2007	1.16
2008	1.2
2009	1.24
2010	1.28
2011	1.32
2012	1.36
2013	1.41
2014	1.45
2015	1.5