Year	Years
1990	71.7
1991	71.7
1992	71.5
1993	71.4
1994	71.1
1995	70.9
1996	70.8
1997	70.9
1998	70.9
1999	71.1
2000	71.3
2001	71.5
2002	71.8
2003	72
2004	72
2005	72.8
2006	73.3
2007	73.7
2008	74.1
2009	74.4
2010	74.6
2011	74.7
2012	74.8
2013	74.9