Select command to calculate average data backed up.

[chandra24in]

Select command to calculate average data backed up.

 

[BaR]

By 'data backed up ' you mean all the filespaces managed by the 'TSM?

If so:
Select sum(capacity)/1024 as "Capacity in GB" from filespaces

 

[marclant]

Additional queries here: http://thobias.org/tsm/sql/

You may find one that does what you are looking for or one that you can adapt.