Year % of adults 2000 22.7386943513115 2005 21.1184802149381 2010 19.6650613220659 2011 19.4000649737553 2012 19.1672518652463 2013 18.9039305348541 2014 18.6507688439383 2015 18.4547031640715 2016 18.2717275325895