B.1. In making rates for the classes of insurance to which this chapter applies, separate consideration shall be given to (i) past and prospective loss experience within and outside this Commonwealth, (ii) conflagration or catastrophe hazards, (iii) a reasonable margin for underwriting profit and contingencies, (iv) dividends, savings or unabsorbed premium deposits allowed or returned by insurers to their policyholders, members or subscribers, (v) past and prospective expenses both countrywide and those specifically applicable to this Commonwealth, (vi) investment income earned or realized by insurers from their unearned premium and loss reserve and the Commission may give separate consideration to investment income earned on surplus funds, (vii) the loss reserving practices, standards and procedures utilized by the insurer, and (viii) all other relevant factors within and outside this Commonwealth. When actual experience or data does not exist, the Commission may consider estimates.2. In the case of fire insurance rates, consideration shall be given to the experience of the fire insurance business during a period of not less than the most recent five-year period for which such experience is available.In the case of workers' compensation insurance rates for volunteer firefighters or volunteer emergency medical services personnel written through the Virginia Worker's Compensation Insurance Plan, the rates shall be calculated based upon the combined experience of both volunteer firefighters or volunteer emergency medical services personnel and paid firefighters or paid emergency medical services personnel, so that the resulting rate is the same for both volunteer and paid members, but in no event shall resulting premiums be less than $40 per year for any volunteer firefighter or volunteer emergency medical services personnel.