Year	Percent
1998-01-01	56.00648117
1999-01-01	69.41098022
2000-01-01	63.09513092
2001-01-01	61.36423111
2002-01-01	64.15146637
2003-01-01	52.66056824
2004-01-01	57.06513214
2005-01-01	48.69277191
2006-01-01	52.68189240
2007-01-01	43.47423553
2008-01-01	32.81579971
2009-01-01	32.09816742
2010-01-01	23.82675362
2011-01-01	22.27966309
2012-01-01	21.55876923
2013-01-01	23.28962708