Year	Measure
1990	0.643
1991	0.651
1992	0.66
1993	0.667
1994	0.675
1995	0.683
1996	0.695
1997	0.706
1998	0.709
1999	0.715
2000	0.725
2001	0.723
2002	0.724
2003	0.731
2004	0.734
2005	0.732
2006	0.736
2007	0.747
2008	0.756
2009	0.764
2010	0.774
2011	0.776
2012	0.779
2013	0.783
2014	0.787
2015	0.789