Year % of total primary 1971 18.9284191131592 1972 15.0944995880127 1974 34.7717514038086 1975 32.3429908752441 1976 30.8730201721191 1984 31.0514297485352 2000 38.1957817077637 2007 49.701789855957 2008 51.6952095031738 2009 52.7935409545898 2010 51.9370918273926 2011 52.1971397399902 2012 52.597339630127 2014 51.3763313293457 2015 51.5728912353516 2017 49.8793487548828 2018 48.7602500915527