6. Section 15 of the Principal Act is amended by adding at the end the following subsection:
“(2) In assessing the amount of ambulance levy payable by a health benefits organization under the Ambulance Service Levy Act 1990 in respect of a return, the Commissioner may, where he or she is not able to determine accurately a matter that is required to be determined for the purpose of assessing that amount, make such a determination of the matter as the Commissioner considers reasonable in the circumstances of the case.”.