Year	Years
1970	1.01
1971	1.04
1972	1.07
1973	1.1
1974	1.13
1975	1.16
1976	1.19
1977	1.22
1978	1.25
1979	1.28
1980	1.32
1981	1.35
1982	1.39
1983	1.42
1984	1.46
1985	1.5
1986	1.54
1987	1.58
1988	1.62
1989	1.66
1990	1.7
1991	1.74
1992	1.79
1993	1.83
1994	1.88
1995	1.93
1996	1.98
1997	2.03
1998	2.08
1999	2.13
2000	2.19
2001	2.24
2002	2.3
2003	2.36
2004	2.41
2005	2.47
2006	2.54
2007	2.6
2008	2.66
2009	2.73
2010	2.8
2011	2.87
2012	2.94
2013	3.01
2014	3.08
2015	3.15