This is very useful information especially for new authors looking for publishers and/or marketing services.
Total Author Solutions ISBN output for 2015, including 657 Archway ISBNs not shown in this section: 24,587.
2015 output did grow slightly at WestBow, by 275, and at Archway, by 37. And Wordclay, defunct for years, inexplicably popped up again in 2015 with 14. But for all other AS brands, including its very first "imprint," AuthorHouse, issued ISBNs fell by hundreds or thousands. Overall, AS's 2015 ISBN output was less than half its 2011 high point, and represents a 45% drop over 2013.
Even allowing for some inconsistencies in the data, that is a really precipitous decline. Pearson, which bought AS in 2012 for the surprisingly low price of $116 million (surprising because then, as now, AS was the largest of the assisted self-pub providers, and by all appearances was still growing), unloaded it in December 2015 to a private equity firm. Looks like that was a good decision.
Meanwhile, DIY platform Createspace--where authors don't have to use ISBNs or can provide their own--continues to be king, with 423,728 ISBNs issued in 2015, an increase of 131,545 over the previous year.