Year % of tax revenue 1990 3.3200914356732287 1991 1.2852089024226412 1992 2.3787501005388885 1993 1.6818863800544575 1994 1.7825746366089301 1995 1.849474248752661 1996 2.0536052531885343 2004 0.8303213645910699 2005 1.0539747469861758 2006 0.6999712145425752 2007 0.7910063012467053 2008 0.7830649312696364 2009 0.7741295441878746 2010 0.7220234160257802 2011 0.48640822340984996 2012 0.4435953463234164 2013 0.24612586081110333 2014 0.4807873275290588 2015 0.41976838760473983 2016 0.4312311851515621 2017 0.3533564421350433 2018 0.3134304775298151 2019 0.3064836942734005 2020 0.45281430708684056 2021 0.5347253663040956