CREATE TABLE table_9181 ("Official Name" TEXT, "Status" TEXT, "Area km 2" FLOAT, "Population" FLOAT, "Census Ranking" TEXT)

what is the census ranking when the area km 2 is 173.4?
SELECT "Census Ranking" FROM table_9181 WHERE "Area km 2" = '173.4'
SELECT "Census Ranking" FROM "table_9181" WHERE "Area km 2" = '173.4'