Year % of adults 2000 22.7347054680514 2005 21.11474524555 2010 19.6614470547798 2011 19.396641205868 2012 19.1639228256335 2013 18.9006504402156 2014 18.6475735153366 2015 18.4515840334826 2016 18.2686753739243