The weekly rate of pension payable in accordance with section 164 shall be increased -
(a) by the amount set out in column (6) of Part 1 of Schedule 4 where the beneficiary has attained pensionable age and is living alone,
(b) by the amount set out in column (7) of Part 1 of Schedule 4 where the beneficiary has attained the age of 80 years, and
(c) by the amount set out in column (8) of Part 1 of Schedule 4 where the beneficiary has attained pensionable age and is ordinarily resident on an island.