Year	Percent
1999-01-01	7.41752880820265
2000-01-01	6.73187774316864
2001-01-01	6.17561115710166
2002-01-01	6.31093507337655
2003-01-01	6.67545842452978
2004-01-01	6.29429911902621
2005-01-01	6.50320169895481
2006-01-01	5.95295201760650
2007-01-01	4.82474474297748
2008-01-01	4.37504595286216
2009-01-01	5.84731340374145
2010-01-01	7.23744682556042
2011-01-01	8.16943523409835
2012-01-01	8.83880614873527
2013-01-01	10.10859278314570
2014-01-01	9.67327778058723
2015-01-01	8.96260709145071
2016-01-01	8.00659821725764
2017-01-01	6.56907487495613