Year	Years
1970	0.3
1971	0.31
1972	0.32
1973	0.33
1974	0.34
1975	0.35
1976	0.36
1977	0.37
1978	0.39
1979	0.4
1980	0.41
1981	0.43
1982	0.44
1983	0.46
1984	0.47
1985	0.49
1986	0.5
1987	0.52
1988	0.54
1989	0.56
1990	0.57
1991	0.59
1992	0.61
1993	0.63
1994	0.66
1995	0.68
1996	0.7
1997	0.72
1998	0.75
1999	0.77
2000	0.8
2001	0.82
2002	0.85
2003	0.88
2004	0.91
2005	0.94
2006	0.97
2007	1
2008	1.03
2009	1.06
2010	1.1
2011	1.13
2012	1.17
2013	1.21
2014	1.25
2015	1.29