Year Percent 1999-01-01 10.8150000000000000 2000-01-01 7.5413500000000000 2001-01-01 5.6622100000000000 2002-01-01 5.4767100000000000 2003-01-01 7.9933500000000000 2004-01-01 11.8014000000000000 2005-01-01 15.3214000000000000 2006-01-01 22.0441000000000000 2007-01-01 29.3730000000000000 2008-01-01 6.7403300000000000 2009-01-01 8.5201300000000000 2010-01-01 5.7141699999999990 2011-01-01 2.5990599999999997 2012-01-01 4.2298900000000000 2013-01-01 5.5448699999999995 2014-01-01 7.1489800000000000 2015-01-01 8.4583100000000000 2016-01-01 7.6575000000000000