Year Percent 1995-01-01 11.8375000000000000 1996-01-01 9.4063200000000000 1997-01-01 5.9472200000000000 1998-01-01 5.0725100000000000 1999-01-01 5.1611400000000005 2000-01-01 4.2453100000000000 2001-01-01 4.2115500000000000 2002-01-01 4.6389500000000000 2003-01-01 4.9749500000000000 2004-01-01 6.4575400000000000 2005-01-01 8.3233300000000000 2006-01-01 9.8000800000000000 2007-01-01 12.2297000000000000 2008-01-01 13.7679999999999990 2009-01-01 14.0598000000000000 2010-01-01 13.5635000000000000 2011-01-01 12.3474000000000000 2012-01-01 13.3706000000000000 2013-01-01 15.2458000000000000 2014-01-01 18.6632000000000000 2015-01-01 22.1376000000000000 2016-01-01 22.0498000000000000