Neb. Rev. Stat. § 15-101: Neb. Rev. Stat. § 15-101

All cities having more than one hundred thousand and less than four hundred thousand inhabitants as determined by the most recent federal decennial census or the most recent revised certified count by the United States Bureau of the Census shall be known as cities of the primary class. The population of a city of the primary class shall consist of the people residing within the territorial boundaries of such city and the residents of any territory duly and properly annexed to such city.