Year	Years
1990	68.3
1991	68.5
1992	68.6
1993	68.6
1994	68.7
1995	68.8
1996	68.9
1997	69
1998	69.1
1999	69.1
2000	69
2001	69
2002	68.9
2003	68.9
2004	68.9
2005	69
2006	69.1
2007	69.3
2008	69.4
2009	69.5
2010	69.7
2011	69.8
2012	69.9
2013	70