Okay, it’s 15 tomes without Friguld update, and an extra 2 added with the update.
Available points per lvl,
lvl 1: 4 AP
lvl 2 to 15: 2 AP per lvl
lvl 16 and above: 3 AP per lvl
Breakdown at lvl 20,
4 + 14 * 2 + 5 * 3 + 15 tomes = 62
Breakdown at lvl 25,
62 + 5 * 3 + 2 tomes = 79
Hmm, seems...