A mutual bank may borrow from any source and in any manner amounts without limit that are required to satisfy its obligations to its depositors. It may borrow for other purposes an aggregate outstanding amount not to exceed
(1) five percent of its total assets at the time of borrowing, exclusive of any sums borrowed under AS 06.15.140 - 06.15.170;
(2) 15 percent of its total assets if borrowing from the Federal Home Loan Bank.