If the director finds that an individual has been overpaid unemployment compensation disability benefits because he or she willfully, for the purpose of obtaining unemployment compensation disability benefits, either made a false statement or representation, with actual knowledge of the falsity thereof, or withheld a material fact, the director shall assess against the individual an amount equal to 30 percent of the overpayment amount. For the purpose of collection, an assessment made pursuant to this section may be treated as an overpayment. Assessments collected under this section shall be deposited in the Unemployment Compensation Disability Fund. No penalty under this section shall be assessed with regard to any false statement or representation made prior to January 1, 1986.