Year	Percent
1991-01-01	10.3222600166705
1992-01-01	10.1015556436446
1993-01-01	10.3669413399037
1994-01-01	10.5130801362846
1995-01-01	10.9102604752633
1996-01-01	11.0130662185382
1997-01-01	11.6376606563379
1998-01-01	12.0072749669048
1999-01-01	12.0021040970496
2000-01-01	12.5861896150592
2001-01-01	12.6129036274955
2002-01-01	12.7587977674396
2003-01-01	12.5082099486268
2004-01-01	12.4928376018280
2005-01-01	12.7966259905190
2006-01-01	12.4227826122448
2007-01-01	12.0548046797415
2008-01-01	12.2399149137144
2009-01-01	12.1839640733465
2010-01-01	11.2996963764286
2011-01-01	11.3596701871740
2012-01-01	11.5835455010604
2013-01-01	11.6120690352511
2014-01-01	11.4286876955295
2015-01-01	11.8882131683662
2016-01-01	12.1481875293230
2017-01-01	12.2539176534070