Year	Years
1970	1.05
1971	1.08
1972	1.11
1973	1.14
1974	1.17
1975	1.21
1976	1.24
1977	1.28
1978	1.31
1979	1.35
1980	1.38
1981	1.42
1982	1.46
1983	1.5
1984	1.54
1985	1.58
1986	1.62
1987	1.66
1988	1.7
1989	1.75
1990	1.8
1991	1.84
1992	1.89
1993	1.95
1994	2
1995	2.06
1996	2.13
1997	2.21
1998	2.29
1999	2.37
2000	2.45
2001	2.53
2002	2.62
2003	2.71
2004	2.8
2005	2.89
2006	2.98
2007	3.07
2008	3.17
2009	3.27
2010	3.37
2011	3.47
2012	3.57
2013	3.68
2014	3.78
2015	3.89