Year	Years
1970	1.05
1971	1.07
1972	1.1
1973	1.14
1974	1.17
1975	1.2
1976	1.23
1977	1.27
1978	1.3
1979	1.34
1980	1.37
1981	1.41
1982	1.45
1983	1.49
1984	1.53
1985	1.57
1986	1.62
1987	1.66
1988	1.71
1989	1.76
1990	1.81
1991	1.86
1992	1.91
1993	1.96
1994	2.01
1995	2.07
1996	2.13
1997	2.2
1998	2.26
1999	2.33
2000	2.4
2001	2.47
2002	2.54
2003	2.61
2004	2.68
2005	2.75
2006	2.82
2007	2.9
2008	2.97
2009	3.05
2010	3.13
2011	3.21
2012	3.29
2013	3.37
2014	3.45
2015	3.54