Year	Years
1990	59.1
1991	59.3
1992	59.5
1993	59.5
1994	59.5
1995	59.7
1996	59.7
1997	59.8
1998	60
1999	60.4
2000	60.9
2001	61.6
2002	62.3
2003	63
2004	63.8
2005	64.5
2006	65.2
2007	65.8
2008	66.2
2009	66.6
2010	66.9
2011	67.2
2012	67.5
2013	67.8