OK, so we're calculating the amount of CPU used by the Sybase engines. The tricky part is with LPARs and processor entitlement, if capped or uncapped, virtual processors, etc. With the LPAR, not sure you're getting a good picture of cpu usage at all since you can potentially be working with a fraction of a processor.
Bottom line though is we pull information from Sybase as it sees it from the OS. Did the 2nd part of my original answer help with drilling in to see which statements were contributing to which activity?