Year	Years
1990	69.2
1991	67.7
1992	68.9
1993	68.9
1994	68.8
1995	68.5
1996	68.5
1997	68.5
1998	68.7
1999	68.9
2000	69.1
2001	69.3
2002	69.4
2003	66.7
2004	65.5
2005	66.6
2006	63.3
2007	64.3
2008	66.6
2009	68.1
2010	68.3
2011	70.6
2012	70.9
2013	71.3