| (a) | - | the sum for which the property might reasonably be expected to let from year to year; or |
| (b) | - | where the property or any part of the property is let and the actual rent received or receivable by the owner in respect thereof is in excess of the sum referred to in clause (a), the amount so received or receivable; or |
| (c) | - | where the property or any part of the property is let and was vacant during the whole or any part of the previous year and owing to such vacancy the actual rent received or receivable by the owner in respect thereof is less than the sum referred to in clause (a), the amount so received or receivable : |