Year	Percent
1991-01-01	14.1129451613279
1992-01-01	14.9505803646559
1993-01-01	16.3727590962881
1994-01-01	16.4817424794556
1995-01-01	15.9770788616481
1996-01-01	16.0240131348974
1997-01-01	15.6019542830808
1998-01-01	15.2647117962840
1999-01-01	15.2911686785626
2000-01-01	14.3154503184435
2001-01-01	14.3019113718089
2002-01-01	15.1935908287062
2003-01-01	15.4582338335821
2004-01-01	15.2731718636786
2005-01-01	14.9309586757419
2006-01-01	13.8298120330062
2007-01-01	12.8525077589295
2008-01-01	13.5794596835210
2009-01-01	17.5071166852766
2010-01-01	18.1490104535246
2011-01-01	17.7798381592199
2012-01-01	18.3767120830391
2013-01-01	18.2751417910455
2014-01-01	17.4326489264276