Year	Years
1990	57.6
1991	57.8
1992	57.9
1993	58
1994	58.2
1995	58.4
1996	58.7
1997	58.9
1998	59.1
1999	59.3
2000	59.5
2001	59.7
2002	60
2003	60.2
2004	60.3
2005	60.6
2006	60.8
2007	61
2008	61.1
2009	61.3
2010	61.5
2011	61.7
2012	61.8
2013	62