Year	Years
1990	69.6
1991	69.7
1992	69.6
1993	69.5
1994	69.4
1995	69.5
1996	69.6
1997	69.6
1998	69.6
1999	69.4
2000	69.4
2001	69.5
2002	69.7
2003	70
2004	70.4
2005	70.9
2006	71.2
2007	71.3
2008	71.3
2009	71.2
2010	71.1
2011	71.1
2012	71.1
2013	71.2