Year	Percent
1997-01-01	6.988530000000000
1998-01-01	5.049710000000000
1999-01-01	14.653600000000000
2000-01-01	12.541400000000000
2001-01-01	12.859000000000002
2002-01-01	14.661800000000000
2003-01-01	14.836100000000000
2004-01-01	16.636200000000000
2005-01-01	16.526000000000000
2006-01-01	18.156800000000000
2007-01-01	21.061999999999998
2008-01-01	17.513600000000000
2009-01-01	19.205800000000000
2010-01-01	19.860400000000000
2011-01-01	18.201800000000000
2012-01-01	19.303000000000000
2013-01-01	22.520400000000000
2014-01-01	24.960300000000000
2015-01-01	28.220300000000000
2016-01-01	28.523400000000000