Year	Years
1990	49
1991	48.7
1992	48.4
1993	48
1994	27
1995	47
1996	46.6
1997	46.7
1998	46.8
1999	47.1
2000	47.5
2001	48.4
2002	49.4
2003	50.7
2004	52.2
2005	53.8
2006	55.3
2007	56.5
2008	57.4
2009	58.2
2010	58.7
2011	59.1
2012	59.5
2013	59.8