a. Specific expenses incurred on such earned marine premiums, consisting of all commissions, agency expenses, taxes, licenses, fees, loss-adjustment expenses, and all other expenses incurred directly and specifically in connection with such premiums, less recoveries or reimbursements on account of or in connection with such commissions or other expenses collected or collectible because of reinsurance or from any other source;

b. General expenses incurred on such earned premiums, consisting of that proportion of general or overhead expenses, such as salaries of officers and employees, printing and stationery, all taxes of this state and of the United States, except as otherwise provided herein, and all other expenses not chargeable specifically to a particular class of insurance, which the net premiums written bear to the total net premiums written by such insurer from all classes of insurance written by it during the current calendar year.

In computing the underwriting profit for purposes of taxation pursuant to section 54:16-3 of this title no deduction in respect to expenses incurred shall be made which in aggregate exceeds forty per cent of the gross premiums on such marine insurances.