Year	Years
1990	72.9
1991	73.2
1992	73.5
1993	73.8
1994	74.1
1995	74.4
1996	74.7
1997	75
1998	75.4
1999	75.7
2000	76.1
2001	76.4
2002	76.6
2003	76.8
2004	77
2005	77.2
2006	77.4
2007	77.4
2008	77.5
2009	77.6
2010	77.7
2011	77.8
2012	77.8
2013	77.9