For annuity contracts that provide cash surrender benefits, the cash surrender benefits available prior to maturity may not be less than the present value as of the date of surrender of    that portion of the maturity value of the paid-up annuity benefit which would be provided under the contract at maturity arising from considerations paid prior to the time of cash surrender reduced by the amount appropriate to reflect any prior withdrawals from or partial surrenders of the contract. The present value must be calculated on the basis of an interest rate not more than one percent higher than the interest rate specified in the contract for accumulating the net considerations to determine the maturity value, decreased by the amount of any indebtedness to the company on the contract, including interest due and accrued, and increased by any existing additional amounts credited by the company to the contract. A cash surrender benefit may not be less than the minimum nonforfeiture amount at that time. The death benefit under the contracts must at least equal the cash surrender benefit.