Year	% of tax revenue
1972	5.031446540880504
1973	14.929577464788732
1974	11.733800350262696
1975	0.30991735537190085
1976	0.4787234042553191
1977	0.6270627062706271
1978	0.29542097488921715
1979	0.2090506640432858
1981	0.015029307148940433
1982	0.03930596889213319
1983	7.167634416710655
1984	2.9389079496795127
1985	1.108098550041259
1986	1.1214727872015435
1987	0.5458568784375224
1988	0.5784107677860753
1989	0.6563488625474212
1990	0.7945516458569807
1991	0.31603897814063736
1992	0.23823704586063135
1993	0.07850662944870901
1994	0.12517136555999286
1995	0.07253384912959382
1996	0.04228776826302992
1997	0.05529517088840907
1998	0.031009812390635036
1999	0.1444008567784169
2000	0.13795821836815136
2001	0.09217534783219876
2002	0.13855809898491417
2003	0.04407285244782661