Year	Years
1970	1.09
1971	1.12
1972	1.15
1973	1.18
1974	1.21
1975	1.24
1976	1.28
1977	1.31
1978	1.34
1979	1.38
1980	1.41
1981	1.45
1982	1.49
1983	1.53
1984	1.56
1985	1.6
1986	1.65
1987	1.69
1988	1.73
1989	1.77
1990	1.82
1991	1.86
1992	1.91
1993	1.96
1994	2.01
1995	2.05
1996	2.11
1997	2.16
1998	2.21
1999	2.27
2000	2.32
2001	2.38
2002	2.44
2003	2.5
2004	2.56
2005	2.62
2006	2.69
2007	2.75
2008	2.82
2009	2.89
2010	2.96
2011	3.03
2012	3.1
2013	3.18
2014	3.25
2015	3.33