Year	Years
1970	0.99
1971	1.03
1972	1.07
1973	1.11
1974	1.15
1975	1.2
1976	1.25
1977	1.3
1978	1.35
1979	1.41
1980	1.47
1981	1.53
1982	1.59
1983	1.66
1984	1.73
1985	1.81
1986	1.89
1987	1.97
1988	2.06
1989	2.16
1990	2.26
1991	2.36
1992	2.47
1993	2.59
1994	2.7
1995	2.83
1996	2.93
1997	3.03
1998	3.13
1999	3.23
2000	3.34
2001	3.44
2002	3.55
2003	3.66
2004	3.77
2005	3.89
2006	4
2007	4.12
2008	4.24
2009	4.36
2010	4.48
2011	4.6
2012	4.73
2013	4.86
2014	4.98
2015	5.12