Section 72. The by-laws of a credit union may provide that upon the death of a member who is a borrower by means of a personal loan upon his note, whether or not there are any endorsers or co-makers thereon, but otherwise unsecured, the liability upon such loan shall cease with respect to the unpaid balance of such loan and any loss thereon may be charged to a contingent fund, which fund shall be created and thereafter maintained by such credit union by contributions from undivided earnings, current earnings or from the borrowers, as determined by the board of directors; provided, however, that the operation of such a provision of the by-laws shall not, in any calendar year, result in charges to the contingent fund in excess of ten percent of the loan reserve, investment reserve, undivided earnings and other surplus accounts in addition to the unexpended balance of contributions by borrowers. Each such charge to the contingent fund shall be reported within ten days thereafter to the commissioner, who may make such orders regarding the operation of the contingent fund as he deems advisable.