Year	Years
1990	71.2
1991	71.1
1992	71.2
1993	71.4
1994	71.7
1995	71.8
1996	72.1
1997	72.3
1998	72.6
1999	72.9
2000	73.3
2001	73.5
2002	73.6
2003	73.7
2004	73.9
2005	74.1
2006	74.2
2007	74.4
2008	74.5
2009	74.6
2010	74.4
2011	74.3
2012	74.3
2013	74.4