Year % (national estimate) 2006 34.05344852656558 2007 33.52518408407202 2008 32.942415379717644 2009 32.2925409581916 2010 31.690858021835194 2011 30.47891365006861 2012 30.982681067340646 2014 29.238624092939855 2015 28.705420457307728 2016 28.755943658110304