Mark, it is more simple to say EVERY immigrant that arrived in 1990 or afterward that have been a net cost to Britain, but that also includes offspring. That is a starter for 10 - once completed there must be a review.
If you are not aware, 6.5 million immigrants have arrived in the last 6 years alone (official figures).
Further, I want Islam completely banned and for them ALL to be deported, it is an invading force not a religion - this is a fact, we need to act decisively NOW.