tion of african economies, resultinr in a wiceninr of their taY base, but also the intrccucticL of new tayes anc a relative im­ provement in tax collection. However, this ratio has varied con­ siderably from one country to ancther, reflectinf cifferent cir­ cumstances and developments. Fer the Ccmcrcs, Medarascar, Mali and Sierra Leone the orCinary revenue/GDP ratic \vas below 15 per cent over the 1979-1981 period, whereas in Alferia, Botswana and Eeypt it has been above 35 per cent. 2/ (Fer f~rther cetails see the statistical annex.) - 3. The local contribution to bucpetary receirts has been rela­ tively stable; most of the changes in revenue rerfcrmance can be attributed to the erratic movements of foreign trade. In general, African economies have remained fairly cepencient on fcr­ eign trade for their J:ublic revenues. TaYes en international trace transacticns for the pericd 1979-1981 accounted for al out a third (median value) of their total current revenue, risinr tc as much as 50 per cent for small African econcmies such as thF Com­ orcs, Mauritius, Swaziland, and the Upper Vclta. (For further cetails see the statistical anneY.) A decline in revenue frclll ta.Yes en foreien trace resulted in a dror in the ratio of current revenue to GDP in BurunCi, Rv1anca, Sierrra Lecne, Swazilan c anc Zaire. In Nigeria, the shortfall in petroleum revenues afversely affectec all ·the taYes related tc this sectcr. In the Unitec Republic of Tanzania, the shortaee of foreirn exchanre con­ strained production in various economic sectors, anc revenue fro!!' sales and other taxes fell as a result. 95 E/ECA /Cf·1. 9/5 Table V .A .1 Evolution of major fiscal indicators {Percentage) Current revenue/GDP TaYes on international trace/current revenue c/ Total public expenciture/GDP Current eYpencitures/GDP Expenditure on apriculture /current expenditure c/ Expenditure on rcacs and transport/current expenditure c/ Expenditure en health /current expenditure£/ 