Year	% of tax revenue
1972	42.5512104283054
1973	43.03977272727273
1974	36.62138216184288
1975	30.567081604426004
1976	32.94765840220386
1977	35.40864356011981
1978	29.245283018867923
1979	26.06076479832373
1980	45.93356242840779
1981	30.251202565473008
1982	34.38095238095238
1983	41.43377885783718
1984	35.42708333333333
1985	22.99128333477173
1986	20.701722073855787
1987	17.08969302006517
1988	12.157620567971769
1989	23.81180332353142
1990	23.37128549156706
1991	26.552410838211333
1992	22.740601427733626
1993	22.333414693678304
1994	18.64767518009168
1995	9.838735950480535
1996	13.509237284191913
1997	13.375202089292376
1998	14.763431712584255
1999	14.676049686589405
2000	22.057928024748026
2001	28.01741756274839
2002	33.658561393968675
2003	34.23153414370273
2004	38.903757473211336
2005	26.60448466758003
2006	26.214205063196843
2007	25.319069281741985
2008	23.526981374659687
2009	20.696450254262242