Year Percent 2004-01-01 4.8621500000000000 2005-01-01 5.5366400000000000 2006-01-01 6.1653400000000005 2007-01-01 6.9641699999999990 2008-01-01 6.6141000000000000 2009-01-01 7.2342900000000000 2010-01-01 19.4464000000000000 2011-01-01 16.2434000000000000 2012-01-01 20.4625000000000000 2013-01-01 24.6225000000000000 2014-01-01 4.9563800000000000 2015-01-01 5.0760200000000000 2016-01-01 4.0542700000000000