The aggregate total amount a mutual savings bank may invest in the following shall not exceed the sum of eighty-five percent of its funds and one hundred percent of its borrowings as permitted under RCW
32.08.140, as now or hereafter amended and RCW
32.08.190, as now or hereafter amended:
(1) Mortgages upon real estate and participations therein;
(2) Contracts for the sale of realty;
(3) Mortgages upon leasehold estates; and
(4) Notes secured by pledges or assignments of first mortgages or real estate contracts.
The limitation of this section shall not apply to GNMA certificates, mortgage backed bonds, mortgage pass-through certificates or other similar securities purchased or held by the bank.