Year	% of tax revenue
1975	1.2658227848101267
1976	5.9405940594059405
1977	12.587412587412588
1978	13.114754098360656
1979	17.77777777777778
1980	13.071200850159407
1981	8.393632416787264
1982	5.291240551356158
1983	2.915798869384112
1984	1.0179715973356793
1985	2.3261448994426943
1986	1.6004901960784315
1987	0.3858074514108607
1988	0.8042895442359249
1989	1.5212840195394277
1990	8.291401572654237
1991	0.8197472530829624
1992	0.13879997402139524