Year	Years
1970	1.03
1971	1.07
1972	1.1
1973	1.14
1974	1.18
1975	1.21
1976	1.25
1977	1.29
1978	1.34
1979	1.38
1980	1.43
1981	1.47
1982	1.52
1983	1.57
1984	1.62
1985	1.67
1986	1.72
1987	1.78
1988	1.84
1989	1.89
1990	1.95
1991	2.02
1992	2.08
1993	2.15
1994	2.21
1995	2.28
1996	2.36
1997	2.43
1998	2.5
1999	2.58
2000	2.66
2001	2.74
2002	2.82
2003	2.91
2004	3
2005	3.08
2006	3.17
2007	3.27
2008	3.36
2009	3.46
2010	3.56
2011	3.66
2012	3.76
2013	3.87
2014	3.97
2015	4.08