On reflection I don't see how an increase in the permit scene can account for a 3x drop in IMCR issues, taking place linearly since 2002.
Those doing the IMCR want to be able to fly in IMC. Everybody getting into the permit scene knows they cannot ever do so legally. They can do it illegally enroute and not get caught but it would take a helluva bold player to ask for an instrument approach somewhere, landing a type which every plane spotter will know cannot fly IFR...
There has to be another reason.
Can't be EASA - timing is wrong.
Can't be any regulatory issue - there have been no changes.
Unlikely to be the schools - they make £2-4k on each IMCR.
The weather is same as ever.
It's also unlikely to be any 'attitude' within the CAA. Most would be IMCR pilots barely come into contact with anything published directly by the CAA.
Can't be the JAA IR - the numbers of private JAA IRs have been single digits per year for years.
The FAA IR might account for a bit of it - we are looking at a drop of ~100 each year, but I would think that is rather more than the # of UK pilots doing the FAA IR.