Year Percent 1995-01-01 28.0030000000000000 1996-01-01 28.1523000000000000 1997-01-01 28.0359000000000000 1998-01-01 22.3756000000000000 1999-01-01 21.3978000000000000 2000-01-01 12.2026000000000000 2001-01-01 11.8048000000000000 2002-01-01 10.3913000000000000 2003-01-01 2.1331000000000000 2004-01-01 1.7436700000000000 2005-01-01 1.6834600000000000 2006-01-01 17.1987000000000000 2007-01-01 12.0622000000000000 2008-01-01 12.3751000000000000 2009-01-01 13.3346000000000000 2010-01-01 10.3900000000000000 2011-01-01 9.0573500000000000 2012-01-01 12.5652000000000000 2013-01-01 6.4715300000000004 2014-01-01 5.8165700000000000 2015-01-01 4.7940900000000000