Year	Years
1990	68.3
1991	68.3
1992	68.4
1993	68.2
1994	68.2
1995	68.3
1996	68.3
1997	68.4
1998	63.7
1999	68.6
2000	68.8
2001	69
2002	69.3
2003	69.5
2004	69.9
2005	70.1
2006	70.4
2007	70.6
2008	70.9
2009	71.1
2010	71.3
2011	71.6
2012	71.8
2013	72