Expiration - amount of data that was expired

I am running TSM 5 and would like to know if there is a way to see how much data (GB/TB) is being expired on a daily basis. I now how to extract the total number of files but have not seen anything with the total size of data expired.

I would use this information to compare how much data is being backed up each night to how much is being expired so I can get a better picture of data growth within the library.

Thanks for your help in advance.

Kevin