Year	Years
1970	1.02
1971	1.05
1972	1.08
1973	1.11
1974	1.14
1975	1.17
1976	1.2
1977	1.23
1978	1.26
1979	1.3
1980	1.33
1981	1.36
1982	1.4
1983	1.44
1984	1.48
1985	1.52
1986	1.55
1987	1.6
1988	1.64
1989	1.68
1990	1.72
1991	1.77
1992	1.81
1993	1.86
1994	1.91
1995	1.96
1996	2.01
1997	2.06
1998	2.11
1999	2.17
2000	2.22
2001	2.28
2002	2.33
2003	2.39
2004	2.45
2005	2.51
2006	2.57
2007	2.64
2008	2.7
2009	2.77
2010	2.84
2011	2.91
2012	2.98
2013	3.05
2014	3.12
2015	3.2