The expense of maintaining the Bureau of Insurance must be assessed annually by the Superintendent of Insurance against all insurers and health maintenance organizations licensed to do business in this State in proportion to their respective direct gross premium written on business in this State during the year ending December 31st immediately preceding the fiscal year for which assessment is made. The annual assessment upon all insurers must be applied to the budget of the bureau for the fiscal year commencing July 1st. For any biennial period, total assessment must be in an amount not exceeding .002 of total direct premiums written. When the superintendent calculates the amount of the annual assessment, the superintendent must consider, among other factors, the staffing level required to administer the responsibilities of the bureau. [1997, c. 79, §2 (AMD).]