Year Percent 1995-01-01 15.27480 1996-01-01 19.68480 1997-01-01 30.85450 1998-01-01 9.59347 1999-01-01 24.87450 2000-01-01 18.15810 2001-01-01 24.61420 2002-01-01 22.14370 2003-01-01 29.17500 2004-01-01 25.39060 2005-01-01 28.40740 2006-01-01 20.68610 2007-01-01 56.47900 2008-01-01 24.59160 2009-01-01 23.36380 2010-01-01 11.18290 2011-01-01 31.85260 2012-01-01 24.01960 2013-01-01 23.42600 2014-01-01 12.02970 2015-01-01 16.26040 2016-01-01 22.01910