Year	Years
1990	70.2
1991	70.2
1992	70
1993	69.7
1994	70.7
1995	71
1996	71.3
1997	71.7
1998	71.9
1999	72.1
2000	72.3
2001	72.4
2002	72.4
2003	72.4
2004	72.4
2005	72.4
2006	72.4
2007	72.4
2008	72.1
2009	72.4
2010	72.4
2011	72.6
2012	72.7
2013	72.9