Year	Percent
1998-01-01	4.88860754054284
1999-01-01	5.31507539899010
2000-01-01	4.99899567418758
2001-01-01	4.70140132487260
2002-01-01	4.53885839433786
2003-01-01	4.34054003309136
2004-01-01	4.75897811685385
2005-01-01	4.50060548246328
2006-01-01	4.07524825968979
2007-01-01	3.79133869192704
2008-01-01	3.50721644495429
2009-01-01	4.38195143178234
2010-01-01	5.79792978326435
2011-01-01	8.01784852985499
2012-01-01	10.89795503068880
2013-01-01	12.18144189643190