flash8
The figures are more or less correct.
In addition to previous posts, the reason for the poor takeup of any European national (and now the JAA) IR is not so much the cost of the flying - the cost of doing 50hrs (55 if a twin) with an instructor, plus other stuff, isn't too important on the scale of the costs of ongoing IFR flying. The main reason for poor takeup is the massive ground school, with a mandatory residential element. As has been mentioned, the UK has the IMC Rating and this gets you into the clouds in the UK adequately. So a full IR is really done for flying into Europe, and the candidate needs to be very seriously motivated. The sort of people who can afford to fly real IFR like that are usually pretty busy, running a business or something like that. It would take most of them years of hard work, in between running their lives, to do the exams. The IR exams are OK for the typical would-be airline pilot who is young and usually has plenty of time.
The 1% or 2% figure is actually much worse than it looks, because (of PRIVATE pilots) most Euro IR holders got their IR years ago, often many years ago, in days when there were easier routes to it. The number of PPL holders who get the current JAA IR is absolutely tiny and much less than 1% (one can see the data on the CAA website).
The CAA license issue data website suggests about 10% of awarded PPLs get the IMC Rating. My own guess is that very few of this 10% actually use it, because of the great difficulty in getting an aeroplane that's good enough for real IFR. And the IMCR is no good outside the UK (except for providing a VMC on top privilege) so it's back to the full IR, whereas an American pilot can do his entire life's flying in the big place called the USA.
Finally, in Europe, only a few countries have an active GA scene. Much of Europe is practically devoid of GA.
So, most people who want an IR do the FAA PPL/IR, and then they need an N-reg plane to get the privileges. Expensive too, need to be an owner, but at least one can get it.