(1) Each insurer that has been authorized to transact property and casualty insurance in this state for a continuous period of less than 3 years shall monthly calculate its premium growth as follows:(a) For the 12-month period ending on the last day of the previous month, obtain the amount of the insurer’s direct and assumed written premiums for the United States and its territories.
(b) For the 12-month period immediately preceding the 12-month period specified in paragraph (a), obtain the amount of the insurer’s direct and assumed written premiums for the United States and its territories.
(c) Subtract the amount of premiums calculated under paragraph (b) from the amount of premiums calculated under paragraph (a).
(d) Divide the amount of premiums determined under paragraph (c) by the amount of premiums determined under paragraph (b).
(2) Until an insurer has held a certificate of authority in this state for 24 months, the insurer shall, instead of making the calculations required under subsection (1), report to the office no later than the last day of each month the insurer’s direct and assumed written premiums from the United States and its territories for the previous month.
(3) If the amount of the premium growth calculated by an insurer under this section exceeds 33 percent, the insurer shall, within 30 days after the end of the 12-month period ending on the last day of the previous month, file with the office a statement of the premium growth calculations under this section. The commission shall adopt rules specifying the form for the report. In response to a report under this section, the office may require the insurer to submit an explanation of the insurer’s pattern of premium growth.
(4) For the purposes of this section, direct and assumed written premiums shall be calculated in the same manner as for the preparation of the insurer’s annual statement under s. 624.424. 
