Year	Measure
1990	0.405
1991	0.408
1992	0.412
1993	0.414
1994	0.418
1995	0.421
1996	0.424
1997	0.428
1998	0.432
1999	0.436
2000	0.444
2001	0.45
2002	0.457
2003	0.464
2004	0.47
2005	0.475
2006	0.477
2007	0.48
2008	0.483
2009	0.488
2010	0.493
2011	0.494
2012	0.498
2013	0.5
2014	0.499
2015	0.482