Collection of taxes, personal; service and return of distress warrants; time allowed

All distress warrants issued by the treasurer for the collection of taxes shall be served by the sheriff of the county in the same manner as an execution issued by the district court. Within nine months, except in counties having a population over one hundred thousand inhabitants and in those counties two years, after receiving the current distress warrants from the county treasurer, the sheriff shall make return of the distress warrants to the treasurer of the county. Such distress warrants shall bear an endorsement of the sheriff showing that (1) the taxes therein described have been collected, (2) upon diligent search no property could be found on which to levy, or (3) the delinquent taxpayer has filed an affidavit with the sheriff before making of return of such distress warrant that such taxpayer is unable by reason of poverty to pay such tax and the sheriff shall certify that the property, if any, of the delinquent taxpayer is not worth in value the cost of advertising such property for sale.