At the top do you see something that says, "Norms based on ____"? That would tell you whether the standard scores you have were done by age or grade level.

I've heard age norms should be used unless the student has been retained. In my daughter's case, all her standard scores were different when using age norms vs. grade norms so you might want to just ask the tester for a printout of both. It should be pretty simple for them to do.