Help me here /vp/, I need to understand something about evolution that I've probably had wrong since the beginning.

If I have a Kadabra and level it up to level 99, then trade and evolve it, will it's stats be worse than a Kadabra I traded and evolved at 16 and then leveled up to 99?

I know evolution affects base stats. What I mean to say is does evolution affect stat GAINS per level?