Amount of Fund.

(a) A minimum balance of $500 million shall be maintained in the Fund.

(b) If, due to the payment of liabilities or claims, the balance of the Fund is reduced below $500 million, the Department, in order to return the Fund to the $500 million level, will require contributions sufficient to fund:

(1) The current shortage below $500 million.

(2) Plus the expected payment of liabilities for the next calendar year.

(3) Plus expenses to administer the Fund for the next calendar year.

(4) Less expected investment earnings on the Fund balance during the next calendar year.