Year	Measure
1990	0.767
1991	0.764
1992	0.766
1993	0.768
1994	0.775
1995	0.782
1996	0.788
1997	0.796
1998	0.805
1999	0.818
2000	0.824
2001	0.835
2002	0.843
2003	0.85
2004	0.853
2005	0.858
2006	0.865
2007	0.869
2008	0.873
2009	0.872
2010	0.876
2011	0.877
2012	0.878
2013	0.888
2014	0.888
2015	0.89