Year	Years
1990	68.6
1991	68.8
1992	68.9
1993	69
1994	69
1995	69
1996	69.2
1997	69.4
1998	69.6
1999	70
2000	70.3
2001	70.6
2002	70.8
2003	71.2
2004	71.9
2005	72.1
2006	72.1
2007	72.1
2008	72.2
2009	72.3
2010	72.4
2011	72.5
2012	72.6
2013	72.5