Year Percent 1999 23.10233 2000 26.05316 2001 28.42339 2002 24.15314 2003 41.23289 2004 26.44972 2005 36.62896 2006 32.19589 2008 30.48838 2010 30.86393 2011 34.19975 2014 33.02067