Year	Years
1970	1.04
1971	1.07
1972	1.1
1973	1.13
1974	1.16
1975	1.19
1976	1.22
1977	1.25
1978	1.29
1979	1.32
1980	1.36
1981	1.4
1982	1.43
1983	1.47
1984	1.51
1985	1.55
1986	1.59
1987	1.64
1988	1.68
1989	1.73
1990	1.77
1991	1.82
1992	1.87
1993	1.92
1994	1.97
1995	2.02
1996	2.08
1997	2.13
1998	2.19
1999	2.25
2000	2.31
2001	2.37
2002	2.43
2003	2.49
2004	2.55
2005	2.62
2006	2.69
2007	2.75
2008	2.82
2009	2.89
2010	2.96
2011	3.04
2012	3.11
2013	3.19
2014	3.26
2015	3.34