Year % of total secondary 1998 17.0018291473389 1999 19.3210697174072 2000 16.9347591400146 2001 16.8260707855225 2002 15.9075698852539 2003 15.8637599945068 2004 16.7177600860596 2005 17.311710357666 2006 17.2617702484131 2007 16.9668998718262 2008 17.6484699249268 2009 17.4405307769775 2010 17.4629096984863 2011 17.7325992584229 2012 18.1667098999023 2013 17.262279510498 2014 17.4902591705322 2015 17.6204490661621 2016 17.5207195281982 2017 17.4972095489502 2018 17.4754695892334 2019 17.3056106567383 2020 17.1744709014893 2021 16.4252109527588 2022 16.5544605255127