Year % of tax revenue 1995 20.9367852288925 1996 27.021567431390547 1997 29.14203697815852 1998 23.47737196907557 2002 13.302080552044803 2003 11.886883631662204 2004 10.467568555074438 2011 4.124213524626829 2012 4.780775737681899 2013 4.44612255944604 2014 3.5151686882408018 2015 3.5379690132218506 2016 2.3692028074018374 2017 2.2164591086491834 2018 2.048095694068675 2019 2.1115112532735276 2020 2.230724784956471 2021 2.2076770691427403