Year	% of tax revenue
1972	4.569055036344756
1973	5.006257822277847
1974	4.952912452040461
1975	3.923414940364093
1976	3.8201663201663205
1977	3.2390412437918377
1978	3.318672530987605
1979	3.513423931057342
1980	3.270564915758176
1981	3.8348082595870205
1982	3.517091483896463
1983	4.240687679083095
1984	5.210855949895616
1985	3.880784532700496
1986	4.20763777726961
1987	4.205478188693166
1988	2.3370394593416175
2001	1.7623806012987968
2002	1.7458807289817413
2003	1.7740900709099876
2004	1.5928522749924228
2005	1.9167867241079697
2006	1.9684824690550193
2007	3.2664970555268917
2008	3.130331764666477
2009	3.2589743976485854
2010	3.522299661461629
2011	3.5048160472237084
2012	3.4815723426151224
2013	3.3057467205825204
2014	3.3142932203990645
2015	3.415489789126209
2016	3.29862129062329
2017	3.2086551494565048
2018	3.2538669901795707
2019	3.091699218213483
2020	3.342320953018073
2021	3.1591049921428747
2022	2.9986091024236776
