Year	Percent
1998-01-01	23.9488
1999-01-01	24.3100
2000-01-01	24.5884
2001-01-01	18.4992
2002-01-01	18.2953
2003-01-01	22.0557
2004-01-01	46.3586
2005-01-01	47.6338
2006-01-01	47.7739
2007-01-01	41.3846
2008-01-01	42.7887
2009-01-01	17.6214
2010-01-01	15.1101
2011-01-01	13.7681
2012-01-01	12.2052
2013-01-01	21.0399
2014-01-01	28.8791