Year	Years
1990	61.8
1991	61.7
1992	61.5
1993	61.3
1994	61.1
1995	60.9
1996	60.8
1997	60.8
1998	61
1999	61.2
2000	61.4
2001	61.6
2002	61.8
2003	61.9
2004	62
2005	62.2
2006	62.5
2007	62.9
2008	63.2
2009	63.5
2010	63.8
2011	64.1
2012	64.4
2013	64.7