On a related note, why would anyone buy their bonds? The oil price has left a huge hole in the budget. They are fighting a real war (with Iran) in Yemen, and a proxy war with Iran everywhere else. Their only asset is oil, which is not going back to $100 in a hurry. If they slash their ludicrously generous welfare system and state largesse they risk domestic unrest.
Not a great combination.
I wouldn't go anywhere near a Saudi bond.