§ Mr. Strangasked the Secretary of State for Social Services on the assumption that the rate of increase in the index of retail prices between 20th October and 20th December, 1970, will be equal to the average rate of it crease in the 10 preced- 420W ing months, what will be the purchasing power of the National Insurance pension on 20th December, 1970, expressed as a percentage of its purchasing power on 20th December, 1969.