Year	Years
1970	1.01
1971	1.05
1972	1.08
1973	1.12
1974	1.16
1975	1.2
1976	1.24
1977	1.29
1978	1.33
1979	1.38
1980	1.43
1981	1.48
1982	1.53
1983	1.58
1984	1.64
1985	1.7
1986	1.76
1987	1.82
1988	1.88
1989	1.95
1990	2.02
1991	2.09
1992	2.16
1993	2.24
1994	2.32
1995	2.41
1996	2.48
1997	2.56
1998	2.65
1999	2.73
2000	2.81
2001	2.9
2002	2.99
2003	3.08
2004	3.17
2005	3.27
2006	3.36
2007	3.46
2008	3.56
2009	3.67
2010	3.77
2011	3.88
2012	3.99
2013	4.1
2014	4.21
2015	4.33