Year	Measure
1990	0.713
1991	0.673
1992	0.666
1993	0.695
1994	0.721
1995	0.747
1996	0.772
1997	0.775
1998	0.78
1999	0.786
2000	0.786
2001	0.785
2002	0.788
2003	0.791
2004	0.789
2005	0.787
2006	0.787
2007	0.787
2008	0.788
2009	0.79
2010	0.792
2011	0.794
2012	0.796
2013	0.787
2014	0.799
2015	0.8