Year	Percent
1991-01-01	19.35499954223630
1992-01-01	19.22699928283690
1993-01-01	17.89999961853030
1994-01-01	15.46500015258790
1995-01-01	12.27600002288820
1996-01-01	12.22000026702880
1997-01-01	13.59099960327150
1998-01-01	15.02400016784670
1999-01-01	14.18799972534180
2000-01-01	13.52999973297120
2001-01-01	12.10900020599370
2002-01-01	11.78800010681150
2003-01-01	10.51500034332280
2004-01-01	9.66300010681152
2005-01-01	9.75500011444092
2006-01-01	9.91699981689453
2007-01-01	9.84599971771240
2008-01-01	10.86699962615970
2009-01-01	15.67199993133540
2010-01-01	16.23100090026860
2011-01-01	15.87300014495850
2012-01-01	16.64999961853030
2013-01-01	14.98299980163570
2014-01-01	13.90900039672850
2015-01-01	13.72599983215330
2016-01-01	13.28600025177000
2017-01-01	12.76500034332280