I assume that the team around him is paid by Andy, so quite a few mouths to feed, so to speak, and I'm sure that he's generous towards his family and their comfort. He's obviously earning a lot of money, but it doesn't all end up in his pocket.
Andy not only has to pay his team salaries but, unless things have changed recently, also their travel, accommodation and subsistence expenses, although as they will all be getting paid substantial salaries, it's possible that the last item no longer applies. Also he will have his legal and financial advisers' fees to meet, as well as medical fees - unless he's covered by medical insurance, although given his occupation the premiums will be high with undoubtedly a number of exclusions regarding injuries.
With regard to the amount he earns, don't forget a fair proportion of it goes out in tax. Unlike many other top players he chooses to remain domiciled here.
As far as I know all the top players remain domiciled in their own countries, with the exception of Djokovic who lives in Monte Carlo. However when the Rich List refers to a person's net worth, I assume that that means their estimated worth after various taxes have been deducted.
Thanks for the informative article flowerpower. I hope the venture works out well for him, although I'm sure that he will have the best business brains onto the job.