Year	% (national estimate)
2006	34.215501095846555
2007	33.647290251311404
2008	33.07002446310538
2009	32.40139138342707
2010	31.793715669369917
2011	30.542774377951265
2012	31.037308512896765
2014	29.257075131200388
2015	28.661746933032322
2016	28.717085711351398