CREATE TABLE table_76797 ("Rank" FLOAT, "Value" TEXT, "Name" TEXT, "Source of wealth" TEXT, "2007 Rank" TEXT)

What source of wealth has a value of 5726m?
SELECT "Source of wealth" FROM table_76797 WHERE "Value" = '£5726m'
SELECT "Source of wealth" FROM "table_76797" WHERE "Value" = '£5726m'