Year Percent 1995-01-01 2.8860200000000003 1996-01-01 8.4476700000000000 1997-01-01 12.4152000000000000 1998-01-01 16.2448000000000000 1999-01-01 33.9284000000000000 2000-01-01 46.6529000000000000 2001-01-01 38.5272000000000000 2002-01-01 29.7686000000000000 2003-01-01 31.2631000000000000 2004-01-01 39.9345000000000000 2005-01-01 53.6202000000000000 2006-01-01 63.8205000000000000 2007-01-01 66.4446000000000000 2008-01-01 53.5824000000000000 2009-01-01 43.6038000000000000 2010-01-01 46.0928000000000000 2011-01-01 41.1372000000000000 2012-01-01 36.7932000000000000 2013-01-01 39.1132000000000000 2014-01-01 34.7356000000000000 2015-01-01 34.9907000000000000 2016-01-01 38.7472000000000000 2017-01-01 38.3268000000000000