At least once in each calendar month during the continuance of work upon any public improvement, the governing body shall receive and consider any partial payment estimate prepared by the architect or engineer. Upon review and approval, the governing body shall pay an estimate in an amount equal to the estimated value of the labor and material furnished plus the material adequately stored. A partial payment estimate must include retentions or retainage as follows: ten percent of each estimate until the project is fifty percent completed with no further retainage on estimates during the continuance of the contract unless unsatisfactory progress or performance is documented. The governing body may, upon completion of ninety-five percent of the contract, pay to the contractor up to ninety-five percent of the amount retained from previous estimates. The remaining amount retained must be paid to the contractor in the amounts and at the times approved by the architect or engineer. The governing body shall make final payment of all moneys due to the contractor following completion of all work, acceptance of the project by the governing body, and the provision of necessary releases. If an architect or engineer is not employed by the governing body for administration of the contract, the contractor, at the end of each calendar month during the continuance of work, may furnish a payment estimate to the governing body. After considering and approving an estimate, the governing body shall draw a warrant upon the proper fund and promptly transmit the warrant to the contractor. The governing body may invest or deposit any retained amount in a financial association or institution so that the contractor’s money retained is earning interest or dividends     for the benefit of the contractor. Any amount invested or deposited must remain in the name of the governing body until final payment of all money due to the contractor is to be made.