Year	Measure
1990	0.849
1991	0.855
1992	0.862
1993	0.87
1994	0.884
1995	0.883
1996	0.888
1997	0.895
1998	0.906
1999	0.911
2000	0.917
2001	0.916
2002	0.918
2003	0.924
2004	0.929
2005	0.931
2006	0.934
2007	0.936
2008	0.936
2009	0.936
2010	0.939
2011	0.941
2012	0.942
2013	0.945
2014	0.948
2015	0.949