Year % of total secondary 1999 31.4168796539307 2000 31.5193405151367 2001 31.5232105255127 2002 31.0389499664307 2003 31.2987899780273 2004 31.3943195343018 2005 32.1100006103516 2006 32.7184295654297 2007 33.4735717773438 2008 33.799991607666 2009 34.5054588317871 2010 35.3577003479004 2011 36.0156784057617 2012 36.4734916687012 2013 37.0663909912109 2014 39.3229217529297 2015 39.4827117919922 2016 39.7609214782715 2017 39.4785995483398 2018 39.7312889099121 2019 39.891429901123 2020 39.7301712036133 2021 39.7060813903809