Year	Years
1970	0.92
1971	0.94
1972	0.97
1973	0.99
1974	1.02
1975	1.05
1976	1.08
1977	1.11
1978	1.14
1979	1.17
1980	1.2
1981	1.23
1982	1.26
1983	1.3
1984	1.33
1985	1.37
1986	1.41
1987	1.44
1988	1.48
1989	1.52
1990	1.56
1991	1.6
1992	1.65
1993	1.69
1994	1.74
1995	1.78
1996	1.83
1997	1.88
1998	1.94
1999	1.99
2000	2.04
2001	2.1
2002	2.15
2003	2.21
2004	2.27
2005	2.33
2006	2.39
2007	2.45
2008	2.51
2009	2.58
2010	2.64
2011	2.71
2012	2.78
2013	2.85
2014	2.92
2015	2.99