Year	% of tax revenue
1975	3.1221303948576673
1976	7.487091222030981
1977	3.9618138424821003
1978	0.6654835847382431
1979	0.260707635009311
1981	3.442661083973017
1982	3.222495894909688
1983	0.24964336661911554
1984	0.0514668039114771
1985	0.04661280298321939
1986	1.8479922189801306
1987	0.026652452025586353
1988	0.8371987781423238
1989	0.01876876876876877
1990	0.015774114677813707
2003	0.001794172527630257
2004	0.0029785839811753492
2005	0.0013199647305423999
2006	0.0015340733021132372
2007	0.018893389675287357
2008	0.378292842393289
2009	0.28243620525821467
2010	0.480252912867646
2011	0.15067235063444825