Year	Years
1990	75.4
1991	75.6
1992	75.9
1993	76.2
1994	76.4
1995	76.6
1996	76.9
1997	77.3
1998	77.7
1999	77.9
2000	78.1
2001	78.3
2002	78.5
2003	78.8
2004	79.1
2005	79.4
2006	79.7
2007	79.8
2008	80
2009	80
2010	80.2
2011	80.3
2012	80.5
2013	80.7