If the amount of bona fide fringe benefits paid by an employer exceeds the bona fide fringe benefits rate in a prevailing wage determination, an employer may credit, up to 20 percent of the basic rate, the amount of excess bona fide fringe benefits against the basic wage rate. If the employer does not have a bona fide fringe benefit amount equal to or more than the prevailing wage bona fide fringe benefit amount, the employer shall pay the difference to the employee in basic wages. If a credit of bona fide fringe benefits is applied pursuant to this subsection, the total wages shall equal or exceed the prevailing wage rate.