Year	Years
1990	62.2
1991	62.4
1992	62.2
1993	61.7
1994	60.6
1995	59
1996	56.9
1997	54.8
1998	52.7
1999	50.6
2000	48.7
2001	46.9
2002	45.7
2003	44.7
2004	43.9
2005	43.5
2006	44
2007	45.1
2008	46.1
2009	47.2
2010	47.8
2011	49.2
2012	50.3
2013	50.7