Section 20 - Special population census: population data1. Any county on behalf of all cities, towns and villages therein or any county, city, town, or village on its own behalf is hereby authorized and empowered to contract with the United States bureau of the census to supervise a special population census for purposes of computation of state assistance payable pursuant to section fifty-four of the state finance law in any year and the cost of such a census shall be an expense of the county, city, town, or village respectively. Such county, city, town, or village shall give written notice to the commissioner of taxation and finance that such a contract has been entered into with the United States bureau of the census within thirty days thereof.2. A county, city, town, or village may request from the United States bureau of the census and pay such bureau for the cost of special data for possible use in apportioning its local legislative body.