Year	Percent
1991-01-01	36.3880004882813
1992-01-01	36.4510002136230
1993-01-01	36.5190010070801
1994-01-01	37.5349998474121
1995-01-01	37.5390014648438
1996-01-01	37.5410003662109
1997-01-01	39.3590011596680
1998-01-01	39.5099983215332
1999-01-01	39.6640014648438
2000-01-01	41.5419998168945
2001-01-01	41.5859985351563
2002-01-01	41.7919998168945
2003-01-01	41.7729988098145
2004-01-01	43.6189994812012
2005-01-01	44.1980018615723
2006-01-01	44.8199996948242
2007-01-01	45.4490013122559
2008-01-01	46.0509986877441
2009-01-01	46.6189994812012
2010-01-01	45.3300018310547
2011-01-01	42.5979995727539
2012-01-01	34.3230018615723
2013-01-01	40.8209991455078
2014-01-01	38.6570014953613
2015-01-01	40.1129989624023
2016-01-01	45.1920013427734
2017-01-01	45.5320014953613