Year	Percent
1998-01-01	24.89090919
1999-01-01	30.60809326
2000-01-01	40.66820526
2001-01-01	35.53422165
2002-01-01	34.72336197
2003-01-01	36.82793808
2004-01-01	35.55260086
2005-01-01	39.52298737
2006-01-01	39.51618195
2007-01-01	44.11473465
2008-01-01	49.03686523
2009-01-01	51.82072067
2010-01-01	42.07705688
2011-01-01	39.70477676
2012-01-01	40.50177002
2013-01-01	42.03815460