Year Percent 2000-01-01 0.285050000000000 2001-01-01 0.294529000000000 2002-01-01 4.097010000000000 2003-01-01 5.702240000000000 2004-01-01 4.961069999999999 2005-01-01 15.364100000000000 2006-01-01 13.981600000000000 2007-01-01 12.545200000000000 2008-01-01 11.210999999999999 2009-01-01 10.442000000000000 2010-01-01 15.742300000000000 2011-01-01 16.940500000000000 2012-01-01 20.760100000000000 2013-01-01 23.372000000000000