Year	Years
1970	0.89
1971	0.91
1972	0.94
1973	0.97
1974	1.01
1975	1.04
1976	1.07
1977	1.11
1978	1.14
1979	1.18
1980	1.21
1981	1.25
1982	1.29
1983	1.33
1984	1.37
1985	1.41
1986	1.46
1987	1.5
1988	1.55
1989	1.6
1990	1.65
1991	1.7
1992	1.75
1993	1.8
1994	1.85
1995	1.91
1996	1.97
1997	2.03
1998	2.09
1999	2.15
2000	2.21
2001	2.28
2002	2.35
2003	2.42
2004	2.49
2005	2.56
2006	2.64
2007	2.72
2008	2.8
2009	2.88
2010	2.96
2011	3.05
2012	3.14
2013	3.23
2014	3.32
2015	3.41