JpGraph Error

[RVRoadTrip]

RE: http://www.opencaching.us/articles.php?page=cog
When I click "Statistics OC Team" from the admin menu (lower left column) I get an error.

It displays an image that says: JpGraph Error: 25121, Empty input data array specified for plot. Must have at least one data point.

It is beyond my ability to figure out what this means. Can anyone help with this?

[sp2ong]

I have corrected start date in stat graph

[RVRoadTrip]

You're my hero!   Thank you very much.

[DudleyGrunt]

This problem has resurfaced in the last few days or so.  If you can fix it again, it would be much appreciated.