Year	Years
1970	1.12
1971	1.15
1972	1.18
1973	1.22
1974	1.25
1975	1.28
1976	1.31
1977	1.35
1978	1.38
1979	1.42
1980	1.45
1981	1.49
1982	1.53
1983	1.57
1984	1.61
1985	1.65
1986	1.69
1987	1.73
1988	1.78
1989	1.82
1990	1.87
1991	1.91
1992	1.96
1993	2.01
1994	2.06
1995	2.11
1996	2.16
1997	2.21
1998	2.27
1999	2.33
2000	2.38
2001	2.44
2002	2.5
2003	2.56
2004	2.63
2005	2.69
2006	2.76
2007	2.82
2008	2.89
2009	2.96
2010	3.04
2011	3.11
2012	3.18
2013	3.26
2014	3.34
2015	3.42