(1)Taxes on income other than agricultural income shall be levied and collected by the Federation, but a prescribed percentage of the net proceeds in any financial year of any such tax, except in so far as those proceeds represent proceeds attributable to Chief Commissioners' Provinces or to taxes payable in respect of Federal emoluments, shall not form part of the revenues of the Federation, but shall be assigned to the Provinces and to the Federated States, if any, within which that tax is leviable in that year, and shall be distributed among the Provinces and those States in such manner as may be prescribed :Provided that-(a)the percentage originally prescribed under this subsection shall not be increased by any subsequent Order in Council ;(b)the Federal Legislature may at any time increase the said taxes by a surcharge for Federal purposes and the whole proceeds of any such surcharge shall form part of the revenues of the Federation.
