Year % of tax revenue 1990 1.8871381458409675 1991 1.223735081526307 1992 1.2930757877173844 1993 1.4493719388265085 1994 4.537970775879811 1995 10.83474511011859 1998 6.70401436132347 1999 3.8683627838318935 2012 0.4294134224100903 2013 0.5883033294467386 2014 0.6841246828561073 2015 0.7241035424706239 2016 0.6981027024711979 2017 0.9078857510143414 2018 1.3307616387065242 2019 1.1341515292965405 2020 1.2836909461672736 2021 1.3603861975168743