"or should I make my decision on the basis of a benchmark with a physical testing" or calling them and asking them would be a good idea.
the other thing you might want to check is whether this is eng stress/strain or true stress strain. that will affect your input and may also affect how you interpret that data. I personally have never seen a stress strain curve specified by thickness.
All I know is that data is based on:
ASTM E8-04 Standard Test Methods for Tension Testing of Metallic Materials
I really have no clue whether it's True Stress/Strain or Engineering Strain.
I will have to give it a try in both ways.
I've found this homepage which seems useful for converting Engineering Stress/Strain to True Stress/strain:
a good first step would be to get a copy of that standard so that you understand what the testing data means. it will usually describe how it can be used as well. it should also answer whether it is true stress/strain or engineering stress and strain but you may have to ask whomever you got the data from for that information.