Year % of tax revenue 1997 4.73513551615973 1998 5.342539426438255 1999 4.444814383219577 2000 4.739651718989306 2001 5.671552423181427 2002 5.120306575337798 2003 5.035936542794889 2004 4.483110900111912 2010 7.265396969124789 2011 16.22825309399786 2012 7.623249971917496 2013 5.154072518903196 2014 4.952924919746817 2015 4.702895031846957 2016 5.67588429771014 2017 5.299519051180191 2018 4.555622478101306 2019 4.529227140484098 2020 5.851913280046053 2021 5.473458580254697