This section has effect as to the circumstances in which basic residual subsidy is payable to housing associations and also, subject to section 54 of this Act, as to the amount of basic residual subsidy so payable.

A housing association shall be entitled to basic residual subsidy for the year 1972-73 if the association's subsidies for the year 1971-72 exceed the withdrawal factor, and the amount of the basic residual subsidy for that year shall be equal to the excess.

A housing association which is entitled to basic residual subsidy for the year 1972-73 shall also be entitled to the subsidy for any subsequent year for which the amount of basic residual subsidy payable to the association for the immediately preceding year exceeds the withdrawal factor, and the amount of the basic residual subsidy shall for each such year be equal to the amount obtained by deducting the withdrawal factor from the amount of the basic residual subsidy payable to the association for the immediately preceding year.

In this section the " association's subsidies for the year 1971-72 " means the aggregate of such sums received or to be received by the association as the Secretary of State determines and notifies the association as representing payments made or to be made to the association for the year 1971-72 under or by reference to any of the enactments described in Parts V and VI of Schedule 1 to this Act.

The withdrawal factor for the purposes of this section shall be determined, in relation to each housing association, by the Secretary of State.

For the purposes of subsection (5) above, the Secretary of State shall determine the number of houses as at the end of the year 1971-72 in respect of which the association's subsidies for the year 1971-72 are payable.

For the year 1972-73 the withdrawal factor is the sum produced by multiplying £5 by the number of houses determined under subsection (6) above.

For each year subsequent to the year 1972-73, the withdrawal factor is the sum produced by multiplying £20 by the number of houses determined under subsection (6) above.