Neb. Rev. Stat. § 23-346.01: Neb. Rev. Stat. § 23-346.01

It shall be the duty of the county clerk, in all counties having a population of one hundred fifty thousand or more inhabitants, on or before December 1, annually, to prepare separate estimates of the supplies, materials, equipment and machinery required for the use of the county officers during the coming year, which by law are not required to be furnished by the state, and, in order to properly estimate the amounts of supplies, materials, equipment and machinery to be needed by the county government, the county clerk shall keep a perpetual inventory of all personal property of the county.