I'm not sure if this is what your looking for or not, but here I go...
CCS is Calls in Centi Seconds (this is the time slot for a call). 1 hour = 36 CCS (60min x 60 seconds divided by 100)
Essentialy this reprents the amount of time the trunks are busy. Lets say you have 60 lines to Audix, the max CCS you could have is 2160. If your CCS gets close to your max number, you should add more lines.
If you want detail on all the columns look at 555-233-505 "Reports for Call Manager"
As for checking how many calls go to voice mail, are you trying to see usage for 1 specific mailbox, or multiple. I use the "list measurement subscriber month 2xxx" command to see how many calls were answered by Audix and how hany times the user logged in to check their messages. If you have multiple Audix accounts you want to check, you can use the ASA repot to run the command and have it save to a .txt file. I use this method to find abbandonned Audix accounts.
Good luck!