CREATE TABLE table_63864 ("Year" FLOAT, "Population" FLOAT, "Five Year % change" TEXT, "Ten Year % change" TEXT, "Rank Among Provinces" FLOAT)

What is the highest population for the province having a rank under 5?
SELECT MAX("Population") FROM table_63864 WHERE "Rank Among Provinces" < '5'
SELECT MAX("Population") FROM "table_63864" WHERE "Rank Among Provinces" < '5'