My archer has a daedric bow, no enchants, that does 41 base damage without arrows selected.
Damage with iron arrows (8 damage) selected: 59 (+18)
Damage with steel arrows (10 damage) selected: 63 (+22)
Damage with daedric arrows (24 damage) selected: 94 (+53)
Notes:
1. She only has 41 base damage on her bow which is low, but she is a permanent level one, so no skills and/or perks are used to boost damage. Obviously, adding skills and perks would increase the damage on a larger scale (along the numbers for my other archer, see above).
2. The 88 damage after patch 1.5 increased over the past several weeks because she leveled archery to 100 - even though no skills/perks are used, you'll still level up the basic skill.
3. The increase from 36 to 88 happened while using the same type arrows and no changes in skills/perks or otherwise that could account for an increase in damage - so it was something patch-related. It wasn't until a few days ago when I changed to daedric arrows that the damage increased to 94 (and an increase in skill level to 100).
4. The plus + damage number listed is the increase from the 41 base damage to the damage increase after a specific type arrow was selected. Note that the plus numbers are higher than the actual arrow damage.
The increase when using daedric arrows - a +53 point increase - is not what I would have expected. That's more than double the base damage, and doesn't make any sense - at least not to me.
I'm more than ever convinced that the math (running in the background) is not adding up correctly.
I guess another option could be that the math (and therefore the DPS) had been wrong all along, and the unexpected increases are the corrections resulting from patch 1.5. However, I would have thought that all archers would have noticed something similar before and after 1.5. But I've only seen similar inputs from 8-9 other archers/players on this and the Steam forum who had unexpected/unexplained damage increases.