Employees compensated on mileage basis

(a) Where an employee's wages are based on mileage, Connecticut adjusted gross income derived from or connected with sources within this state is determined by multiplying the employee's gross wages from the employment, wherever earned, determined as if the nonresident were a resident, by a fraction, the numerator of which is the employee's total mileage traveled in Connecticut and the denominator of which is the employee's total mileage upon which the employer computes total wages.