Year	Years
1970	1.06
1971	1.09
1972	1.12
1973	1.15
1974	1.18
1975	1.21
1976	1.24
1977	1.27
1978	1.31
1979	1.34
1980	1.38
1981	1.41
1982	1.45
1983	1.49
1984	1.53
1985	1.57
1986	1.61
1987	1.65
1988	1.69
1989	1.74
1990	1.78
1991	1.83
1992	1.87
1993	1.92
1994	1.97
1995	2.02
1996	2.07
1997	2.12
1998	2.18
1999	2.23
2000	2.29
2001	2.34
2002	2.4
2003	2.46
2004	2.52
2005	2.59
2006	2.65
2007	2.71
2008	2.78
2009	2.85
2010	2.92
2011	2.99
2012	3.06
2013	3.13
2014	3.21
2015	3.29