Year	Years
1970	1.41
1971	1.45
1972	1.48
1973	1.52
1974	1.56
1975	1.59
1976	1.63
1977	1.67
1978	1.7
1979	1.74
1980	1.78
1981	1.81
1982	1.85
1983	1.88
1984	1.92
1985	1.95
1986	1.99
1987	2.02
1988	2.05
1989	2.08
1990	2.1
1991	2.13
1992	2.15
1993	2.17
1994	2.19
1995	2.21
1996	2.22
1997	2.24
1998	2.26
1999	2.29
2000	2.31
2001	2.34
2002	2.37
2003	2.4
2004	2.43
2005	2.47
2006	2.51
2007	2.55
2008	2.59
2009	2.63
2010	2.68
2011	2.72
2012	2.77
2013	2.82
2014	2.87
2015	2.92