Twelve years ago, Mr. Lawton rolled a $31,000 retiring allowance into an RRSP that subsequently earned 11.4% compounded semiannually. Three years ago he transferred the funds to an RRIF. Since then, he has been withdrawing $2400 at the end of each quarter. If the RRIF earns 9.4% compounded quarterly, how much longer can the withdrawals continue? (Do not round intermediate calculations and round up the number of payments, n, to the next whole number.)