Year	Years
1990	58.6
1991	58.6
1992	58.8
1993	58.7
1994	58.8
1995	58.9
1996	59.1
1997	59.2
1998	59.2
1999	59.1
2000	59
2001	58.9
2002	58.8
2003	58.8
2004	58.9
2005	59
2006	59.4
2007	59.7
2008	60
2009	60.5
2010	61
2011	61.7
2012	62.4
2013	63