Year	Years
1990	74.8
1991	75.1
1992	75.3
1993	75.5
1994	75.7
1995	75.8
1996	76
1997	76.1
1998	76.2
1999	76.4
2000	76.7
2001	77.1
2002	77.6
2003	78.1
2004	78.5
2005	78.9
2006	79.2
2007	79.4
2008	79.4
2009	79.6
2010	79.9
2011	80.2
2012	80.4
2013	80.4