(1) The denominator of the payroll factor is the total compensation paid everywhere by the taxpayer during the income year for the production of apportionable income as provided in ARM 42.26.243. The numerator of the payroll factor is the total amount paid in this state during the income year by the taxpayer for compensation. With respect to all personnel except enginemen and trainmen performing services on interstate trains, compensation paid to such employees shall be included in the numerator as provided in ARM 42.26.244. With respect to enginemen and trainmen performing services on interstate trains, compensation paid to such employees shall be included in the numerator of the payroll factor in the ratio which their services performed in this state bear to their services performed everywhere. Compensation for services performed in this state shall be deemed to be the compensation reported or required to be reported by such employees for determination of their income tax liability to this state.