Year	Years
1990	78.1
1991	78.3
1992	78.5
1993	78.7
1994	78.8
1995	78.9
1996	79.1
1997	79.3
1998	79.5
1999	79.7
2000	79.9
2001	80.2
2002	80.5
2003	80.8
2004	81.1
2005	81.3
2006	81.5
2007	81.8
2008	82
2009	82.2
2010	82.5
2011	82.7
2012	82.8
2013	82.8