Is that 100% from all 3 ?
it's +100 avg for practice. Meaning : when you buy a fast trainer, you give him few trainings (3 bars/practice).
If the first or the second are below 100, like a +80, +85 don't get disappointed. Give 5-6 trainings and if you see
+85, +100, +95, +120, +115, + 90, + 125 ,then it's ok.

Hey, hi t11_fan, happy to see you again
Well, you 're absolutely right. This thing it's very frustrated.
Here we have two cases.
If you buy a fast trainer, try to test him in 4-5 games to see his performance. If he starts he 5-6-4-5-6 sell him.
(I know, too bad )
It's a bad program or it doesn't fit in your team and the chances that he 'll perform better with raising his quality, are very few.
If a fast trainer was playing good but have a bad form for few games then there is a hope.
All above it's from personal experience and style of playing and always there are exceptions.

Also, every season is not the same for training but farming too.
The season at Christmas period I 've done a good farming. About 150 T and over 500 boosters.
I also bought a good offer from Nordeus, with many T and boosters, with the half price.
That was good because after Christmas, the period was very dry of farming.