The board of supervisors shall canvass the returns of each city and each parcel of unincorporated territory, if any, separately, and shall order and declare the district created and established of the cities and territory in which a majority of those who voted on the proposition voted in favor of the creation of the district if the total number of voters in such approving cities and territory is not less than two-thirds the number of voters within the district as first proposed, according to the register used at the election.