CREATE TABLE table_61983 ("Official Name" TEXT, "Status" TEXT, "Area km 2" FLOAT, "Population" FLOAT, "Census Ranking" TEXT)

What is the area of the community with a census ranking of 636 of 5,008?
SELECT AVG("Area km 2") FROM table_61983 WHERE "Census Ranking" = '636 of 5,008'
SELECT AVG("Area km 2") FROM "table_61983" WHERE "Census Ranking" = '636 of 5,008'