Year Percent 1995-01-01 6.886760000000001 1996-01-01 9.342660000000000 1997-01-01 14.921200000000000 1998-01-01 18.903000000000000 1999-01-01 25.522300000000000 2000-01-01 26.997100000000000 2001-01-01 24.266300000000000 2002-01-01 36.701500000000000 2003-01-01 40.668600000000000 2004-01-01 29.991100000000000 2005-01-01 37.516100000000000 2006-01-01 19.676900000000000 2007-01-01 22.253100000000000 2008-01-01 23.780000000000000 2009-01-01 27.141900000000000 2010-01-01 20.516800000000000 2011-01-01 15.856200000000000 2012-01-01 14.899500000000000 2013-01-01 11.976800000000000 2014-01-01 11.880200000000000 2015-01-01 11.754700000000000 2016-01-01 11.840300000000000