This is some big news, 8% of frontlist! [George Walkley in the comments points out that it’s UP to 8% of Frontlist]
UK publishers are snappng at the heels of those in the US for e-book sales, with the UK’s largest house revealing the digital format accounts for around 8% of frontlist sales by volume.
via UK e-books grow to Amazonian stature | theBookseller.com.
Eoin Purcell's Blog 
8% of frontlist in publication *at most* – the average is of course lower.
Sorry, that should read:
8% of frontlist, in publication month, *at most* – the average is of course lower.
Thanks George,
I’ll make a note, even though it’s at most, it seems to me that that is an impressive result even so.
All the best,
Eoin