Year	Measure
1990	0.733
1991	0.729
1992	0.718
1993	0.71
1994	0.701
1995	0.7
1996	0.701
1997	0.704
1998	0.703
1999	0.709
2000	0.72
2001	0.727
2002	0.733
2003	0.741
2004	0.748
2005	0.754
2006	0.761
2007	0.769
2008	0.776
2009	0.773
2010	0.785
2011	0.792
2012	0.799
2013	0.803
2014	0.805
2015	0.804