Conversation so far:
Why did Robbie leave Take That?
After drug problems, the band offered Robbie an ultimatum; he was to adhere to the band's responsibilities or leave before their scheduled world tour. Williams chose the latter.
When did Jason leave Take That?
Jason Orange left Take That in 2014 because he did not wish to commit to recording and promoting a new album.

Question: What year did Robbie leave?
Self-contained rewrite: What year did Robbie leave Take That?