Year	Measure
2000	0.527
2001	0.542
2002	0.554
2003	0.553
2004	0.563
2005	0.569
2006	0.587
2007	0.592
2008	0.59
2009	0.589
2010	0.58
2011	0.583
2012	0.586
2013	0.582
2014	0.582
2015	0.592