Year	Measure
1990	0.782
1991	0.79
1992	0.795
1993	0.799
1994	0.803
1995	0.808
1996	0.817
1997	0.826
1998	0.834
1999	0.848
2000	0.854
2001	0.86
2002	0.865
2003	0.867
2004	0.874
2005	0.88
2006	0.877
2007	0.887
2008	0.888
2009	0.884
2010	0.894
2011	0.892
2012	0.892
2013	0.892
2014	0.896
2015	0.898