The controller performance breakdown pie chart appears to be wrong

The controller performance breakdown pie chart appears to be wrong. Regardless of which controller action i click on, the 'Remainder' is ALWAYS 50%. Not only that, but the information shown when mousing over the sections of the pie chart doesn't seem to make sense.
eg with a 30 minute time window:
Controller
/canned_reports/project_status
1.0 call
8285ms total per call
612008125 ms exclusive per call
7386941.9%

Those last 2 numbers are really not making much sense to me. Are they wrong or am i misinterpreting the results?