Oregon Revised Statutes Revenue and Taxation § 317.122

(a) The amount of any assessments paid by the insurer during the tax year pursuant to ORS 656.612; or

(b) The total profit attributable to the workers' compensation line of business, net of reinsurance and including all investment gain attributable to the workers' compensation line of business, determined in the manner prescribed under ORS 731.574 by the Director of the Department of Consumer and Business Services, with the modifications under ORS 317.655 attributable to the workers' compensation line of business, and then apportioned in accordance with ORS 317.660 and multiplied by the corporate tax rate set forth in ORS 317.061. In making the apportionment under ORS 317.660 for purposes of this paragraph, the insurance sales factor shall be determined using only items attributable to the workers' compensation line of business.