CREATE TABLE table_21378 ("Official Name" CLOB, "Status" CLOB, "Area km 2" CLOB, "Population" FLOAT, "Census Ranking" CLOB)

What is Petersville's census ranking?
SELECT "Census Ranking" FROM table_21378 WHERE "Official Name" = 'Petersville'
SELECT "Census Ranking" FROM "table_21378" WHERE "Official Name" = 'Petersville'