This article shall apply to any locality that has adopted zoning pursuant to Article 7 (§ 15.2-2280 et seq.) of Chapter 22 of Title 15.2 and that (i) has a population of at least 20,000 and has a population growth rate of at least 5% or (ii) has population growth of 15% or more. For the purposes of this section, population growth shall be the difference in population from the next-to-latest to the latest decennial census year, based on population reported by the United States Bureau of the Census.