Year	Years
1990	72.1
1991	72.5
1992	72.7
1993	73
1994	73.3
1995	73.6
1996	74
1997	74.2
1998	74.3
1999	74.6
2000	75.1
2001	75.3
2002	75.4
2003	75.4
2004	75.6
2005	75.6
2006	75.8
2007	75.9
2008	75.7
2009	75.5
2010	75.7
2011	76.2
2012	76
2013	75.5