The 8th also has a non-UK PhD; are we exporting all our PhDs or just not producing anyone suitable, I wonder??!
It may be subject specific. I was on a committee last year and none of the surprisingly numerous US-based candidates made it onto the shortlist (lack of publications / relevant teaching experience when compared to UK/European candidates at the same career stage) and we appointed two UK PhDs in the end. But I feel sorry for the UK PhDs - they have to finish in 3-4 years to meet research council expectations and keep our completion records looking good, but then we compare them on an equal basis to candidates in systems that have been allowed to take years longer and thus rack up teaching and publications. It's pretty much essential for them to do a postdoc to compete on equal terms and as we all know they're harder to come by these days.