Year	Measure
1990	0.386
1991	0.393
1992	0.4
1993	0.408
1994	0.415
1995	0.423
1996	0.432
1997	0.441
1998	0.45
1999	0.459
2000	0.468
2001	0.476
2002	0.484
2003	0.491
2004	0.499
2005	0.506
2006	0.513
2007	0.52
2008	0.523
2009	0.535
2010	0.545
2011	0.557
2012	0.565
2013	0.57
2014	0.575
2015	0.579