Do the listing fees run on a calendar basis, or on each...

Do the listing fees run on a calendar basis, or on each anniversary of listing/admission?

If it's the former, and assuming the ASX isn't one to hand out refunds, the fees would be a sunk cost and de-listing won't exactly save them any direct costs up until when the next year's worth of fees fall due. Maybe some admin savings courtesy of less stringent reporting and communications?