Year	Percent
1991-01-01	33.4045445225596
1992-01-01	32.9100869950438
1993-01-01	33.3504220694406
1994-01-01	29.5770919849269
1995-01-01	32.0304982457374
1996-01-01	30.8744111494152
1997-01-01	31.2415234771790
1998-01-01	30.6628743536528
1999-01-01	30.2512439605838
2000-01-01	29.3836450425144
2001-01-01	27.6286068145438
2002-01-01	27.4397427741457
2003-01-01	23.0583408069471
2004-01-01	24.2282319264128
2005-01-01	23.0297006045309
2006-01-01	20.2535174399876
2007-01-01	19.4061895338755
2008-01-01	20.6899710823791
2009-01-01	22.6360285763796
2010-01-01	24.3366601073509
2011-01-01	24.2293952752842
2012-01-01	26.8455740221942
2013-01-01	27.3085283972740
2014-01-01	25.8078210327098
2015-01-01	24.6796478219627
2016-01-01	24.8808644874127
2017-01-01	24.4507894327729