Sec. 1. PURPOSE. The purpose of this article is to restate and amend the provisions of former law creating and governing a police officers pension system in each city in this state having a population of two million or more, according to the most recent federal decennial census, and to reflect changes agreed to by the city and the board of trustees of the pension system under Section 27 of this article. The pension system shall continue to operate regardless of whether the city's population falls below two million.