Module datasheet vs .pan file coefficients

Which is more accurate for temperature coefficients when one has both a .pan file and a module datasheet for a custom module in SAM? When we import .pan files into SAM, the coefficients seem to be slightly different (and come in with different units) than when we manually enter them into SAM.
Example: One module has Voc Coefficient of -0.27%/°C in the datasheet, but converting the units on the one in the .pan gives -0.282%/°C.

Thanks Paul. 
Apologies for the delayed response. I just now learned I had a reply to my question. I must have missed the box to be notified of replies last time.

We usually use the manufacturer's datasheets for the coefficients, yes. However, we recently learned that there is a way to import the module information from a .pan file into SAM. When we import the .pan file, we get different coefficients than what the manufacturer's datasheet shows us. I was hoping for some insight as to which source is more accurate for the coefficients (data sheet or .pan file) when we have both available.

Thanks,
Jen

Thank you for the input Paul!

Perhaps the answer depends on where the PAN file came from?