I don't have any data. One of the problems with tax havens is that they're typically rather secretive and it's very difficult to get the data. There have been a number of estimates, but they vary widely as to the amount of tax that is avoided by the use of tax havens. But even that doesn't tell us who benefits and who loses from that. So while we do believe there are serious problems, I'm afraid I can't provide an answer to your question.
On April 14th, 2008. See this statement in context.