Year % of total secondary 1999 20.6647701263428 2000 20.4642295837402 2001 20.2015800476074 2002 19.9486694335938 2003 20.1407794952393 2004 20.3534202575684 2005 20.9233303070068 2006 21.4045104980469 2007 22.3051795959473 2008 22.7304992675781 2009 23.2733306884766 2010 23.9444198608398 2011 24.6771106719971 2012 25.3114891052246 2013 25.2389297485352 2014 26.9083309173584 2015 27.1751499176025 2016 27.7123508453369 2017 27.690860748291 2018 28.1631698608398 2019 28.3940505981445 2020 28.4859600067139 2021 28.5057506561279 2022 28.4161491394043