Year	Years
1990	77
1991	77
1992	77.1
1993	77.3
1994	77.5
1995	77.6
1996	77.6
1997	77.7
1998	77.8
1999	77.9
2000	78
2001	78.3
2002	78.4
2003	78.5
2004	78.7
2005	78.9
2006	79.2
2007	79.4
2008	79.5
2009	79.5
2010	79.6
2011	79.7
2012	79.8
2013	79.8