4The basic value of an Electricity Board for any year shall be their share of the basic electricity rateable value determined in accordance with paragraph 5 of this Schedule adjusted as mentioned in paragraph 6 of this Schedule by reference to the excess or deficiency of the Board's output, as calculated and certified by the Board, in the twelve months ending with 31st December falling next but one before the beginning of the year for which the basic value is being ascertained, as compared with the Board's standard output.
5(1)Subject to sub-paragraph (2) of this paragraph, the basic electricity rateable value shall be taken to be £47,212,610; and the share thereof of each respectively of the Electricity Boards set out in the following table shall be the percentage of that sum so set out in relation to that Board.
| Electricity Board | Percentage |
|---|---|
| Generating Board | 50.000 |
| London Area | 7.055 |
| South Eastern Area | 3.454 |
| Southern Area | 4.256 |
| South Western Area | 2.073 |
| Eastern Area | 4.949 |
| East Midlands Area | 4.204 |
| Midlands Area | 4.990 |
| South Wales Area | 2.359 |
| Merseyside and North Wales Area | 3.047 |
| Yorkshire Area | 4.972 |
| North Eastern Area | 3.107 |
| North Western Area | 5.534 |
(2)If it appears to the Minister that by reason of any substantial change of circumstances it is expedient so to do, he may by order made after consultation with the Electricity Council and with such associations of local authorities as appear to him to be concerned, and with any local authority with whom consultation appears to him to be desirable, vary the sum which under sub-paragraph (1) of this paragraph is to be taken to be the basic electricity rateable value ; but an order under this sub-paragraph shall not have effect until approved by a resolution of each House of Parliament.
6The adjustment mentioned in paragraph 4 of this Schedule shall be effected by multiplying the Board's share of the basic electricity rateable value by the fraction of which the numerator is the Board's standard output increased by one-fifth of the excess mentioned in the said paragraph 4 or, as the case may be, decreased by one-fifth of the deficiency so mentioned, and the denominator is the Board's standard output.