Year Percent 1999-01-01 32.4790000000000000 2000-01-01 21.6337000000000000 2001-01-01 16.6710000000000000 2002-01-01 14.2842000000000000 2003-01-01 12.5694000000000000 2004-01-01 11.1389000000000000 2005-01-01 11.3781000000000000 2006-01-01 8.5028300000000000 2007-01-01 7.7955300000000000 2008-01-01 6.4298800000000010 2009-01-01 1.5665600000000000 2010-01-01 1.3928700000000000 2011-01-01 1.2112399999999999 2012-01-01 1.0049600000000000 2013-01-01 0.9198200000000001 2014-01-01 2.8022099999999996 2015-01-01 3.7056100000000000 2016-01-01 6.6073800000000000