Paragraph 4
The period to be taken into account by an assessment of the extent of a claimant's disablement shall be the period (beginning not earlier than the end of the injury benefit period, and limited by reference either to the claimant's life or to a definite date) during which the claimant has suffered and may be expected to continue to suffer from the relevant loss of faculty :
Provided that if on any assessment the condition of the claimant is not such, having regard to the possibility of changes therein (whether predictable or not), as to allow of a final assessment being made up to the end of the said period—
a provisional assessment shall be made, taking into account such shorter period only as seems reasonable having regard to his condition and that possibility ; and
on the next assessment the period to be taken into account shall begin with the end of the period taken into account by the provisional assessment.