Year % (national estimate) 1960 75.72 1970 59.78 1989 36.9 1991 57.475 1992 40.3 1998 70.99 1999 71 2000 52.772 2006 35.02 2010 42.899 2013 55.766 2015 46.513 2017 45.968 2022 38.895