I want to know the answer to the following question:
What is the current spectator seating capacity of Twickenham Stadium?
All the background I'm provided with is that "Three Aviva Premiership rugby union teams are based in London, (London Irish, Saracens, and Harlequins), although currently only Harlequins and Saracens play their home games within Greater London.". Is that enough to answer the question?