Each fire protection district shall contract, prior to the imposition of a benefit charge, for the administration and collection of the benefit charge by each county treasurer, who shall deduct a percent, as provided by contract to reimburse the county for expenses incurred by the county assessor and county treasurer in the administration of the resolution and this chapter. The county treasurer shall make distributions each year, as the charges are collected, in the amount of the benefit charges imposed on behalf of each district, less the deduction provided for in the contract.