Don't know TBH, but I'm sure someone else was asking the same in the asteroids forum.
I've temporarily stopped crunching A@H, initially to crunch some Rosetta (& to lower temps) but currently crunching LHC & as they have a (very rare) glut of WUs atm! lol.
I'll grab a few WUs & see what times I get, although it's going to be hard to judge, I've just looked through my valid results & the times vary from ~7000-14,000s! At the end of June most were 9000-11,000s, but before that they were 7000-8000s, at least for a little while. Last 20 included some 9000-11,000s (which are the more typical ones btw) but also some 12,000-15,000s!
[update] Damn they came through quickly! Meant to grab at most a dozen WUs & got nearly 60 instead!