Year	Years
1970	0.18
1971	0.19
1972	0.19
1973	0.2
1974	0.21
1975	0.22
1976	0.23
1977	0.24
1978	0.25
1979	0.26
1980	0.27
1981	0.28
1982	0.3
1983	0.31
1984	0.32
1985	0.34
1986	0.36
1987	0.37
1988	0.39
1989	0.41
1990	0.43
1991	0.45
1992	0.48
1993	0.5
1994	0.53
1995	0.56
1996	0.58
1997	0.61
1998	0.64
1999	0.67
2000	0.7
2001	0.73
2002	0.77
2003	0.8
2004	0.83
2005	0.87
2006	0.9
2007	0.94
2008	0.98
2009	1.01
2010	1.05
2011	1.09
2012	1.13
2013	1.17
2014	1.21
2015	1.25