Year	% of tax revenue
1972	5.660377358490567
1973	4.225352112676056
1974	5.078809106830122
1975	9.917355371900827
1976	12.127659574468085
1977	14.85148514851485
1978	12.09115847225153
1979	20.31480570585342
1980	20.004111842105264
1981	17.038224537848805
1982	15.711157280026953
1983	10.508257295829877
1984	14.042926673581743
1985	12.692050768203073
1986	14.841091191682077
1987	13.462836118535385
1988	12.401958592317667
1989	11.026660890796675
1990	11.350737797956867
1991	10.350276534105873
1992	8.725431804645623
1993	5.8705512909979065
1994	6.0022650056625135
1995	5.261121856866538
1996	5.130915882580964
1997	5.205645373637369
1998	5.302677918798591
1999	5.003489687372145
2000	4.527985810011826
2001	5.597907853616131
2002	5.844623615007406
2003	6.4208891244682915
2004	7.0687104037517035
2005	6.829913855504527
2006	6.698090760701368
2007	6.996322068166531
2008	6.121019335451409
2009	5.264396105947639
2010	5.554776648941091
2011	5.958343106529422
2012	5.954646257518234
2013	5.802972042900351
2014	6.1414210947227765
2015	5.729879292640848
2016	4.082941246411767
2017	5.103518185009545
2018	5.67469688271927
2019	5.6453675017195355
2020	5.533122811554024