Year	Years
1970	8.95
1971	9.09
1972	9.23
1973	9.37
1974	9.51
1975	9.66
1976	9.8
1977	9.94
1978	10.08
1979	10.23
1980	10.37
1981	10.51
1982	10.66
1983	10.8
1984	10.94
1985	11.08
1986	11.22
1987	11.37
1988	11.51
1989	11.65
1990	11.79
1991	11.93
1992	12.07
1993	12.2
1994	12.34
1995	12.48
1996	12.61
1997	12.75
1998	12.88
1999	13.01
2000	13.14
2001	13.27
2002	13.4
2003	13.52
2004	13.65
2005	13.77
2006	13.89
2007	14.01
2008	14.12
2009	14.24
2010	14.36
2011	14.47
2012	14.58
2013	14.69
2014	14.8
2015	14.9