Year	Years
1990	73
1991	73.3
1992	73.6
1993	73.9
1994	74.2
1995	74.4
1996	74.2
1997	74.7
1998	74.7
1999	74.6
2000	74.6
2001	74.7
2002	74.7
2003	74.8
2004	74.9
2005	75.1
2006	75.2
2007	75.2
2008	75.3
2009	75.5
2010	75.6
2011	67.7
2012	75.3
2013	75.6