Year	Years
1990	58.5
1991	57.2
1992	60.1
1993	60.9
1994	61.6
1995	62.4
1996	63.2
1997	63.9
1998	64.6
1999	65.2
2000	65.8
2001	66.3
2002	66.8
2003	67.2
2004	67.6
2005	67.9
2006	68.1
2007	68.1
2008	68.4
2009	68.5
2010	68.6
2011	68.9
2012	69.2
2013	69.5