So, I thought I'd look at how the tickets for their tour are selling given it's pretty much around the corner:
Most dates are now near sold out, with tickets mostly still available at the very back of the venues. Birmingham, for example, has literally three tickets remaining. Newcastle has improved drastically since the last time I wrote an update on this; they've gone from about 25% of tickets sold to about 70% of tickets sold. I have noticed though that for some dates, you can get tickets for as cheap as £20, so maybe that's why.
All in all, I'd suggest they're looking at an average of maybe 80%+ sold out for each date.