Year	Years
1990	72.8
1991	72.9
1992	72.7
1993	72.9
1994	72.9
1995	73
1996	73.2
1997	73.2
1998	73.2
1999	73.5
2000	73.9
2001	74.2
2002	74.4
2003	74.7
2004	74.9
2005	75.1
2006	75.1
2007	75.2
2008	75.4
2009	75.6
2010	75.8
2011	76.1
2012	76.4
2013	76.6