(b) notify the Minister that the person wishes to repay the amount, plus any charges calculated under this paragraph, in approximately equal monthly instalments to be deducted from the person’s benefit for the lesser of
[...]
calculated as at the expiration of the 30 day period in accordance with Life Table No. 2 of Vital Statistics Report, No. 4 — Life Tables for Canada and Regions — 1941 and 1931, published by the Department of Trade and Commerce, Dominion Bureau of Statistics, Ottawa, 1947.