Year	Measure
1990	0.736
1991	0.741
1992	0.746
1993	0.75
1994	0.754
1995	0.758
1996	0.762
1997	0.767
1998	0.776
1999	0.779
2000	0.783
2001	0.786
2002	0.79
2003	0.797
2004	0.805
2005	0.809
2006	0.808
2007	0.813
2008	0.815
2009	0.819
2010	0.826
2011	0.821
2012	0.828
2013	0.847
2014	0.853
2015	0.856