Year	Years
1990	52.5
1991	53.1
1992	53.9
1993	54.7
1994	55.4
1995	56
1996	56.4
1997	56.7
1998	56.8
1999	49.3
2000	49.3
2001	57.7
2002	58
2003	58.3
2004	58.7
2005	59
2006	59.5
2007	60
2008	60.4
2009	60.7
2010	61
2011	61.3
2012	61.7
2013	62.1