In response to the demands, Mexico City received a greater degree of autonomy, with the 1987 elaboration the first Statute of Government (''Estatuto de Gobierno'') and the creation of an assembly of representatives.  In the 1990s, this autonomy was further expanded, and since 1997, residents can directly elect the head of government to Mexico City and the representatives of a unicameral Legislative Assembly, which succeeded the previous assembly, by popular vote.