Year Percent 1999-01-01 2.1244000000000000 2000-01-01 2.1244000000000000 2001-01-01 2.1981400000000000 2002-01-01 1.8747500000000000 2003-01-01 2.3400200000000000 2004-01-01 2.5921300000000000 2005-01-01 2.7524900000000003 2006-01-01 3.3991700000000000 2007-01-01 3.3702800000000000 2008-01-01 2.7688300000000000 2009-01-01 3.2789599999999997 2010-01-01 4.0297800000000010 2011-01-01 3.7770500000000000 2012-01-01 3.6818000000000000 2013-01-01 3.9337900000000000