Year % of tax revenue 2001 23.30462863293864 2002 21.061843640606767 2003 24.64428002276608 2004 20.270176843798744 2005 17.412182356611165 2006 20.06269592476489 2007 17.415275809946287 2008 17.215931901337886 2009 16.17230201482734 2010 16.055491833003778 2011 15.35692605570752 2012 16.449203754699575 2013 18.600029970069826 2014 17.725315471112772 2015 16.00915388164937 2016 14.358194905222843 2017 13.610006340809843 2018 15.25733896720455 2019 16.22550975306502 2020 17.196933186652867 2021 18.772797685593087