3.—(1) The issue fee under paragraph 2(2) above is determined as follows:
(a)for a number of units not exceeding 15, the fee is the relevant amount;
(b)for a number of units exceeding 15 and forming a multiple of 5, the fee is the relevant amount plus the relevant amount for each multiple of 5 in excess of 15;
(c)for a number of units exceeding 15 and not forming a multiple of 5, the fee is the fee applicable under paragraph (b) above for the multiple next above that number.
(2) For the purposes of determining the fee under sub-paragraph (1) above—
(a)units in which colour television receivers are installed or used shall be counted first; and
(b)if in any group of 5 units in excess of 15 there are installed or used both black and white television receivers and colour television receivers, all the television receivers in that group shall be treated as if they were colour television receivers.