Year	Percent
1996-01-01	22.8341
1997-01-01	22.7433
1998-01-01	13.7841
1999-01-01	21.6595
2000-01-01	22.1281
2001-01-01	19.2533
2002-01-01	21.4553
2003-01-01	12.0238
2004-01-01	19.9244
2005-01-01	16.5804
2006-01-01	19.1812
2007-01-01	21.5406
2008-01-01	22.4405
2009-01-01	19.0818
2010-01-01	22.0009
2011-01-01	22.0140
2012-01-01	19.1948
2013-01-01	19.6185
2014-01-01	19.4813
2015-01-01	16.1830
2016-01-01	17.1942