Constitutional Reform and Governance Bill

I am not, in principle, against the idea of referendums relating to the European Union; in fact, I am on record as saying that I think we ought to have an all-singing, all-dancing referendum on membership of the European Union. However, may I just ask the hon. Gentleman how many of the treaties that have been passed in the past 20 years does he think would have needed to be the subject of a referendum?