Year	% (national estimate)
2006	17.807521145003978
2007	16.12835104161179
2008	15.894397539265395
2009	15.09512505556183
2010	14.639571774463002
2012	13.658198826201383
2014	11.977753396662044
2015	15.20829728990508
2016	14.316115651017686