Year	Years
1970	1.12
1971	1.16
1972	1.21
1973	1.26
1974	1.31
1975	1.36
1976	1.42
1977	1.48
1978	1.54
1979	1.6
1980	1.67
1981	1.74
1982	1.81
1983	1.89
1984	1.97
1985	2.06
1986	2.14
1987	2.24
1988	2.34
1989	2.44
1990	2.55
1991	2.66
1992	2.78
1993	2.91
1994	3.04
1995	3.17
1996	3.3
1997	3.43
1998	3.57
1999	3.7
2000	3.83
2001	3.97
2002	4.1
2003	4.24
2004	4.38
2005	4.52
2006	4.66
2007	4.8
2008	4.94
2009	5.08
2010	5.23
2011	5.37
2012	5.51
2013	5.66
2014	5.8
2015	5.95