To be fair, that underestimates his wealth since technically he owns the entire country. Revisionist Westerners refuse to recognize his divine eternal rule and the divine eternal rule of his father and grandfather. 
edit: Actually, that makes me realize that list I looked at ignores other declared monarchs, like Qatar or the Saudi's.
edit: Actually, that makes me realize that list I looked at ignores other declared monarchs, like Qatar or the Saudi's.