Year	Years
1990	75.7
1991	76
1992	76.3
1993	76.5
1994	76.7
1995	76.8
1996	76.9
1997	77.2
1998	77.4
1999	77.6
2000	77.8
2001	78
2002	78.2
2003	78.5
2004	78.8
2005	79.1
2006	79.3
2007	79.4
2008	79.5
2009	79.7
2010	80
2011	80.4
2012	80.8
2013	81