In The Simpsons, series 13, episode 10; Half-Decent Proposal, Marge is reminded of her former boyfriend Artie Ziff by a news report in which Kent Brockman says these lines:
Gentlemen, start your envy! Men's world magazine has listed the one hundred richest men in the country, and coming in at number five is Springfield native, Artie Ziff.
Now, it makes sense that local news would mention a local person being on that list, but isn't Mr Burns an obvious omission? His main character traits are wealth and cruelty. Wouldn't he be in the top five? Is it possible he's not on the list at all?
So, is Artie richer than Monty at that point? Any tv/comic/comicon sources?