Year	Years
1990	68
1991	67.9
1992	67.7
1993	67.3
1994	66.4
1995	66
1996	66.7
1997	67.9
1998	68.8
1999	69.1
2000	69.3
2001	69.8
2002	70.2
2003	70.3
2004	70.1
2005	69.7
2006	69.4
2007	69.4
2008	69.6
2009	69.8
2010	70.2
2011	70.9
2012	71.5
2013	71.9