Year	Years
1970	1.06
1971	1.11
1972	1.15
1973	1.2
1974	1.25
1975	1.3
1976	1.35
1977	1.41
1978	1.47
1979	1.53
1980	1.59
1981	1.66
1982	1.74
1983	1.81
1984	1.9
1985	1.98
1986	2.08
1987	2.18
1988	2.28
1989	2.39
1990	2.52
1991	2.65
1992	2.79
1993	2.94
1994	3.1
1995	3.28
1996	3.43
1997	3.58
1998	3.73
1999	3.87
2000	4.02
2001	4.17
2002	4.32
2003	4.47
2004	4.62
2005	4.77
2006	4.92
2007	5.07
2008	5.22
2009	5.37
2010	5.52
2011	5.68
2012	5.83
2013	5.98
2014	6.14
2015	6.3