Year	Percent
1988-01-01	12.4943
1989-01-01	12.4943
1990-01-01	12.4943
1991-01-01	12.4943
1992-01-01	12.4943
1993-01-01	78.7800
1994-01-01	45.4475
1995-01-01	26.5217
1996-01-01	21.3333
1997-01-01	20.5650
1998-01-01	21.7283
1999-01-01	23.2525
2000-01-01	20.2008
2001-01-01	17.4308
2002-01-01	17.2257
2003-01-01	17.8945
2004-01-01	22.2569
2005-01-01	22.9444
2006-01-01	20.7279
2007-01-01	19.6259
2008-01-01	20.1670
2009-01-01	18.2136
2010-01-01	17.4337
2011-01-01	16.3499
2012-01-01	16.7803
2013-01-01	15.8144
2014-01-01	13.4311
2015-01-01	13.8165
2016-01-01	13.8182