Year	Measure
1990	0.705
1991	0.713
1992	0.72
1993	0.725
1994	0.728
1995	0.731
1996	0.738
1997	0.746
1998	0.753
1999	0.764
2000	0.771
2001	0.776
2002	0.77
2003	0.775
2004	0.78
2005	0.782
2006	0.788
2007	0.792
2008	0.794
2009	0.802
2010	0.816
2011	0.822
2012	0.823
2013	0.825
2014	0.826
2015	0.827