Players improve until???

[Humanfly]

I have started a ML yesterday with Ajax. Match mode players.
Suddenly Imbrahimovic got injuryed for 3 weeks.
So i let Anastasiou play because he's not that bad in the game.
His age is 31. After the game Anastasious stats where improved!!!
I don't understand that a player from 31 still improves.
In a old ML i had Mbo Mpenza and his stats came down when he was 28?
Does anyone has an explanation for this?

 

[Original?]

Every single player on the game has an individual development curve, evidently Mpenza's peaks a long way before Anastasious.