In the event any person fails to pay a sum, required to be paid to the City under this Chapter (hereinafter the "principal sum"), within ninety (90) days after the sum becomes due and owing to the City, a civil penalty is imposed on such person equal to thirty-three and thirty-three one-hundredths percent (33.33 %) of the sum of the following two items:
(a) The unpaid principal sum due and owing to the City under this Chapter,
(b) Court costs incurred in obtaining a judgment against such person for the unpaid principal sum due and owing to the City under this Chapter.