It would be very difficult to be definitive about it in that there are obviously a considerable number of additional factors that came into play over the same 30 year period. However, there is a definite view that holidays were definitely “abroad” in NI which, I think, is stronger than that feeling in the rest of the UK. It wasn’t until very recently (ie post peace agreement) that the NI tourist board really found it’s feet whereas English Heritage has been running very strongly for many years.

I’m sure there must be some comparable figures on it somewhere. What you’d need to know would be the percentage of residents of NI taking holidays abroad vs the percentage on the mainland doing the same thing.

What may not have sunk in yet is that the increased security makes the airports safer. After all, Israels airline is supposedly the safest in the world due to the over the top approach that they take to security. And, in light of your other post, no, they don’t rely on technology: they have trained security people who ask all kinds of questions to a) determine if you are a terrorist (and they appear to operate on the assumption that everyone is until they’re convinced otherwise which is, of course, the safest thing to do) and b) determine if someone else could have planted something on you (eg they asked us where and when we’d bought our case, not just if anyone could have placed something in it).