Every person that has a permit to engage in the business of distributing butter shall pay a fee of one dollar ($1), plus twenty cents ($0.20) for each 1,000 pounds, or part of 1,000 pounds, over and above the first 5,000 pounds of butter which such person distributed during each of the three-month periods ending February 28th, May 31st, August 31st, and November 30th. Such fees shall be paid to the director during the first week of March, June, September, and December, respectively.