hero stat gains?
 

where can I find the hero stats for damage gain per level and attack speed gain per level?
The game database does not contain them.

Can't find an easy stat info, but if you really need it you can try using the champion builder at the tools section of leaguecraft.com. Look at the stats for the champion at level 1 and level 18, and divide the difference by 17. If the stat gain is linear (the stat gain per level is constant, not changing), you'll get the champion stat increase per level. I've checked the damage and attack speed for Akali at a few levels and they seem to be linear. Dunno about other champs though.