Year	Percent
1998-01-01	5.07228322641063
1999-01-01	4.51551086803065
2000-01-01	4.02901184641404
2001-01-01	4.00883194333964
2002-01-01	4.99331265022614
2003-01-01	6.26494506426242
2004-01-01	6.62254667323464
2005-01-01	7.58066955546265
2006-01-01	7.64743687254027
2007-01-01	7.96366713114289
2008-01-01	7.55199064485009
2009-01-01	9.43288576618750
2010-01-01	10.76982094459010
2011-01-01	12.68105637929710
2012-01-01	15.53027942852010
2013-01-01	16.18379741311100
2014-01-01	13.89508764489470
2015-01-01	12.44468566628960
2016-01-01	11.06845575928470
2017-01-01	8.87040678196100