Thanks Both
Howard, I see this is your first post - welcome to the forum! Thanks for the details, which have been added to the database. No surprises with either of yours, which is great.
Brian, we had yours on the database, but good to be able to fill in the details. Again, no surprises, happily.
The more data we gather, the more certain we can be about when the changes happened, and the more easily we'll be able to spot the "odd" sets. Like I did with the loudspeaker survey previously, I'll post some conclusions once I've had a bit more data.
Thanks again,
Mark