No policy of legal expense insurance may be issued in this state unless the premium rates for the insurance have been filed with and approved by the office. Premium rates shall be established and justified in accordance with generally accepted insurance principles, including, but not limited to, the experience or judgment of the insurer making the rate filing or actuarial computations. The office may disapprove rates that are excessive, inadequate, or unfairly discriminatory. Rates are not unfairly discriminatory because they are averaged broadly among persons insured under group, blanket, or franchise policies. The office may require the submission of any other information reasonably necessary in determining whether to approve or disapprove a filing made under this section or s. 642.025.