Year Percent 1993 41.77964 1994 33.09515 1995 28.96089 1996 41.60411 1997 33.51273 1998 42.35769 1999 39.89919 2000 39.9677 2001 40.68009 2002 42.42597 2003 38.66491 2004 50.09553 2005 48.48395 2006 48.24554 2007 52.52223 2008 44.30609 2009 56.20745 2010 55.61856 2011 59.48544 2012 67.85471 2013 63.78698 2014 64.87134 2015 69.51072 2016 70.7364