Amount of XP a player gets is multiplied, among other things, by his hidden parameter. Some managers call it Talent. It is basically what makes a player fast or slow trainer. We don't know it, it's hidden, we can only say if it's big or not so big by dividing Value by Wage (or by Overall quality). Therefore, it's impossible to say how much XP exactly a player needs to train a skill by 1%, or for 1 point to SA.
There're also other parameters that affect getting XP. Age and amount of stars come to mind.
Also, please refer to this excellent guide by All Svanberg:
https://forum.topeleven.com/tutorial...ng-system.html