Year	Years
1970	1.04
1971	1.07
1972	1.1
1973	1.13
1974	1.16
1975	1.19
1976	1.22
1977	1.26
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	1.63
1988	1.67
1989	1.72
1990	1.76
1991	1.81
1992	1.86
1993	1.9
1994	1.95
1995	2
1996	2.05
1997	2.11
1998	2.16
1999	2.21
2000	2.27
2001	2.33
2002	2.38
2003	2.44
2004	2.5
2005	2.57
2006	2.63
2007	2.69
2008	2.76
2009	2.83
2010	2.9
2011	2.97
2012	3.04
2013	3.11
2014	3.18
2015	3.26