Year % (national estimate) 1978 27.65 1983 43.79 1986 44.38 1987 44.92 1988 47 1989 49.9 1990 48.13 2009 56 2010 55.42 2011 55.6 2012 53.6 2013 54.83 2014 52.71 2015 55.357 2016 56.518 2017 55.193 2018 54.395 2019 54.736