Year	Measure
1990	0.669
1991	0.664
1992	0.663
1993	0.666
1994	0.68
1995	0.695
1996	0.707
1997	0.719
1998	0.73
1999	0.739
2000	0.749
2001	0.759
2002	0.765
2003	0.771
2004	0.777
2005	0.783
2006	0.793
2007	0.8
2008	0.803
2009	0.803
2010	0.808
2011	0.815
2012	0.817
2013	0.82
2014	0.823
2015	0.827