Year	% of tax revenue
1981	8.187543736878936
1982	7.866666666666666
1983	8.35036496350365
1984	7.768641905301957
1985	8.574091332712023
1986	8.436532507739939
1987	7.921245421245421
1988	7.208101667990468
1989	9.436510999614049
1990	8.577508593877885
1991	9.463532248342375
1992	13.604887983706721
1993	13.895512681552136
1994	13.70798797704709
1995	18.446991827829752
1996	15.238093487559071
1997	8.721323175578133
1998	6.068455449818214
1999	5.560458088858076
2000	4.619182632294536
2001	3.7937115300753903
2002	3.5509195009423564
2003	3.3557415442968863
2004	0.743339881244283
2005	-0.017725792005956933
2006	-0.004043333755637081
2007	-0.003669947454346399
2008	-0.0008046546272453217
2009	-0.0009064686248547222
2010	-0.00014496885585746662