Average distance between fillups not between minimum and maximum distances

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Enter fillups.
2. Select the Statistics button.

Expected behavior: The average distance between fillups would be between the 
minimum and maximum distances between fillups.

Actual behavior: The average distance is 139, the minimum distance is 210, and 
the maximum distance is 481.

Mileage version: 3.0.8
Android version: 2.3.7
Device: Google Nexus S

If you need the fillup data, let me know and I'll add it.

Original issue reported on code.google.com by [email protected] on 9 Feb 2012 at 8:15