Year	Years
1970	1.1
1971	1.14
1972	1.18
1973	1.22
1974	1.27
1975	1.31
1976	1.36
1977	1.41
1978	1.46
1979	1.52
1980	1.57
1981	1.63
1982	1.7
1983	1.76
1984	1.83
1985	1.91
1986	1.98
1987	2.07
1988	2.15
1989	2.24
1990	2.34
1991	2.44
1992	2.55
1993	2.66
1994	2.78
1995	2.91
1996	3.03
1997	3.14
1998	3.25
1999	3.37
2000	3.48
2001	3.59
2002	3.7
2003	3.81
2004	3.92
2005	4.03
2006	4.15
2007	4.26
2008	4.37
2009	4.48
2010	4.6
2011	4.71
2012	4.82
2013	4.93
2014	5.05
2015	5.16