Year	Years
1990	52.3
1991	52.6
1992	52.8
1993	53
1994	53.1
1995	53.3
1996	53.4
1997	53.5
1998	53.7
1999	53.9
2000	54.1
2001	54.3
2002	54.5
2003	54.8
2004	55
2005	55.2
2006	55.5
2007	55.7
2008	56
2009	56.2
2010	56.5
2011	56.7
2012	56.8
2013	57.2