How to find out compression per job on tape

I am trying to find a way if possible of finding out how much a particular job compressed on to a tape.  I know you can find out the compression ratio on a tape, but I am trying to identify how well a particular backup job has compressed. 

The byte count of the job under job history only tells you the raw amount of data, it doesnt I dont think tell you what the tape drive managed to compress on the the tape for a particular job.

A, Is it possible to find this info and B, where is it?

Thanks