Year	Measure
1990	0.714
1991	0.716
1992	0.716
1993	0.72
1994	0.725
1995	0.729
1996	0.733
1997	0.738
1998	0.734
1999	0.741
2000	0.75
2001	0.749
2002	0.753
2003	0.757
2004	0.761
2005	0.766
2006	0.771
2007	0.775
2008	0.779
2009	0.781
2010	0.78
2011	0.785
2012	0.792
2013	0.793
2014	0.794
2015	0.795