Year	Years
1990	64.1
1991	64.1
1992	64
1993	63.8
1994	63.8
1995	63.8
1996	63.8
1997	63.7
1998	63.8
1999	63.9
2000	64.2
2001	64.4
2002	64.7
2003	64.9
2004	65.1
2005	65.3
2006	65.4
2007	65.6
2008	65.7
2009	65.8
2010	65.9
2011	66
2012	66
2013	66.1