Year % of total taxes 1974 24.561133353865106 1975 27.75032509752926 1976 26.690391459074732 1977 26.154534272615454 1978 23.404255319148938 1979 22.819913130638156 1980 21.899954798854903 1981 23.11702996419373 1982 22.441802043208842 1983 20.95776808398447 1984 19.833830421815083 1985 18.947955909027485 1986 18.191402837605807 1987 17.60036108751062 1988 19.454439147251957 1989 18.925984739920214 1990 18.6004099072498 1991 22.10427863060067 1992 23.450835376555865 1993 26.61967686710892 1994 28.872949487507316 1995 29.900123160459202 1996 29.910221959895 1997 27.521209117226615 1998 32.01427091084854 1999 33.5128557454935 2000 36.00280065985243 2001 36.780908697255946 2002 38.26907604524059 2003 41.26347573777453 2004 43.29579810990366 2005 44.26522318599926 2006 47.4727145246583 2007 52.57870308709308 2008 52.781605093689386 2009 58.77728264750763 2010 55.20633687735792 2011 54.81436910238098 2012 52.254155028256974 2013 53.43943942324031 2014 55.21131301519817 2015 50.394085928800045 2016 48.99060101187593 2017 51.24203607281979 2018 50.14850826900029