Year	Years
1990	56.9
1991	57.2
1992	57.6
1993	58
1994	58.3
1995	58.6
1996	58.9
1997	59.1
1998	59.4
1999	59.9
2000	60.2
2001	60.6
2002	60.9
2003	61.2
2004	61.6
2005	61.9
2006	62.2
2007	62.4
2008	62.6
2009	62.8
2010	63
2011	63.3
2012	63.5
2013	63.7