Year Percent 1998-01-01 7.0000000000000000 1999-01-01 8.7000000000000000 2000-01-01 8.7000000000000000 2001-01-01 9.0000000000000000 2002-01-01 7.6000000000000000 2003-01-01 14.8000000000000000 2004-01-01 9.5000000000000000 2005-01-01 6.3000000000000000 2006-01-01 4.1000000000000000 2007-01-01 2.7000000000000000 2008-01-01 2.2000000000000000 2009-01-01 2.7000000000000000 2010-01-01 3.0270099999999998 2011-01-01 2.8927500000000000 2012-01-01 3.2333200000000000 2013-01-01 3.5029400000000000 2014-01-01 3.9534599999999998 2015-01-01 3.9254900000000000 2016-01-01 4.2923200000000000