Year	Percent
1991-01-01	3.79500007629395
1992-01-01	6.71000003814697
1993-01-01	7.17999982833862
1994-01-01	7.46299982070923
1995-01-01	7.06799983978271
1996-01-01	8.78499984741211
1997-01-01	5.53200006484985
1998-01-01	8.21199989318848
1999-01-01	9.60299968719482
2000-01-01	7.45399999618530
2001-01-01	7.71000003814697
2002-01-01	11.26099967956540
2003-01-01	10.17399978637700
2004-01-01	10.84500026702880
2005-01-01	10.66699981689450
2006-01-01	8.84200000762939
2007-01-01	8.75199985504150
2008-01-01	9.21800041198730
2009-01-01	9.89700031280518
2010-01-01	7.11700010299683
2011-01-01	6.71000003814697
2012-01-01	6.53100013732910
2013-01-01	6.33400011062622
2014-01-01	6.34299993515015
2015-01-01	3.82100009918213
2016-01-01	4.07700014114380
2017-01-01	4.60400009155273