Client shows wrong stats

Not sure if this is a bug or not. It either is or the documentation of champion stats is wrong.

Braum has 576.16 health. (+87 per level) > At level 2 that is 663.16 health. Not 639. Janna has 487.05 health (+78 per level) . At level 3 that is 643.05 health. Not 603. Braum has 26.72 armor (+4.5 per level) > At level 2 that is 31.55 armor. Not 33. Janna has 19.384 armor (+3.8 per level) . At level 3 that is 26.984 armor. Not 25.

These are two separate examples that show how the client does not show the correct stats for the champions in the game. The base stats are correct however the scaling ones are not. I was experimenting with optimal rune pages and such and found miscalculations but then after testing without runes or masteries I noticed it was the game that showed the incorrect statistics. My only idea is the growth stats are an average and not a constant increase level to level.

http://puu.sh/q6OcB/76956ccbba.jpg http://puu.sh/q6OnA/828f84c48f.jpg