Hello Juan,
Please check a similar question and solution for it in : https://forum.mendix.com/link/questions/97312
We must have to do it with custom styles.
Hmmm, my answer on 97312 is indeed a good start. You would use:
.MyClass :after{ content: '%'; right: +5px; }
but you still have to turn 0,24 into 24 and worse: turn 1,00 into 100 without turning 0,24 into 024. And to make it work on native, do the same in javascript.