Year	Years
1970	1.03
1971	1.07
1972	1.12
1973	1.16
1974	1.21
1975	1.27
1976	1.32
1977	1.38
1978	1.44
1979	1.5
1980	1.57
1981	1.64
1982	1.72
1983	1.8
1984	1.88
1985	1.97
1986	2.06
1987	2.16
1988	2.26
1989	2.37
1990	2.49
1991	2.61
1992	2.74
1993	2.88
1994	3.02
1995	3.17
1996	3.31
1997	3.45
1998	3.6
1999	3.74
2000	3.89
2001	4.03
2002	4.17
2003	4.32
2004	4.46
2005	4.6
2006	4.74
2007	4.88
2008	5.02
2009	5.16
2010	5.29
2011	5.43
2012	5.56
2013	5.7
2014	5.83
2015	5.96