Year	Measure
1990	0.783
1991	0.786
1992	0.794
1993	0.798
1994	0.808
1995	0.815
1996	0.822
1997	0.83
1998	0.839
1999	0.847
2000	0.856
2001	0.863
2002	0.866
2003	0.869
2004	0.864
2005	0.869
2006	0.873
2007	0.876
2008	0.878
2009	0.874
2010	0.878
2011	0.884
2012	0.887
2013	0.89
2014	0.893
2015	0.895