Year % of tax revenue 1972 0.5738132498695859 1973 0.47596382674916626 1974 0.154320987654321 1975 0.07293946024799426 1976 0.05936479667557139 1977 0.08172160174339421 1978 0.07185628742514971 1979 0.06098800569221381 1980 0.10495014867937726 1981 0.07717240314863405 1982 0.06636580833554552 1983 0.06026274557068839 1984 0.06611570247933878 1985 0.061431350465854274 1986 0.06663493574488305 1987 0.05261209648000871 1988 0.038250231988514606 1989 0.01657795439364314 1990 0.0230943671371018 1991 0.020963184514407016 1994 0.013540961408260006 1995 0.00885646205427746 1996 0.003917205935350433 1997 0.014296868985692133 1998 0.012206835185238725 1999 0.007248893788604134 2000 0.00549340935440875 2001 0.0019468997012899601 2002 0.0013953696055011052 2003 -0.0013863780042811353 2004 -0.002912665062053005 2005 0.018541236471882088 2006 -0.06087156578922141 2007 -0.022818982599361534 2008 -0.024861550813360462 2009 -0.024197551806459498 2010 -0.02465646467390684 2011 -0.003785660363913304 2012 -0.026773022142989187 2013 -0.007732708747525024 2014 -0.023297102322480095 2015 -0.023530057687858097 2016 -0.021929058525358144 2017 -0.02339620834047194 2018 -0.022232686951513484 2019 -0.01974637620528199 2020 0.005423733558214157 2021 0.007004786604179523 2022 0.006771856165775038