Year	Percent
1997-01-01	21.531999999999996
1998-01-01	21.701600000000000
1999-01-01	27.007100000000000
2000-01-01	31.175000000000000
2001-01-01	32.584900000000000
2002-01-01	21.370800000000000
2003-01-01	16.982000000000000
2004-01-01	20.368800000000000
2005-01-01	25.312500000000000
2006-01-01	28.191300000000000
2007-01-01	30.310100000000000
2008-01-01	35.895700000000000
2009-01-01	44.322400000000000
2010-01-01	51.964100000000000
2011-01-01	56.299300000000000
2012-01-01	57.798500000000000
2013-01-01	56.662500000000000
2014-01-01	58.248300000000000
2015-01-01	60.359500000000000