Facing some harder comparisons, e-book sales posted their slowest growth rates in 2010 in October. Still, sales jumped 112.4%, to $40.7 million, from the 14 publishers who reported results to the AAP’s monthly sales program.For the first 10 months of the year, e-book sales from the 14 houses rose 171.3%, to $345.3%, 8.7% of the trade sales of reporting publishers.The three adult categories all had declines in October and for the 10 months of 2010 adult hardcover sales from 17 reporting houses fell 7.7%, and sales from 9 mass market houses were down 14.3%. Sales of trade paperbacks from 19 publishers were flat.