Year	Years
1990	65.8
1991	66.6
1992	67.4
1993	68.2
1994	68.9
1995	69.6
1996	70.2
1997	70.9
1998	71.5
1999	72.1
2000	72.6
2001	73.3
2002	74
2003	74.9
2004	75.8
2005	76.7
2006	77.3
2007	77.8
2008	78.2
2009	78.6
2010	78.9
2011	79.1
2012	79.2
2013	79.3