I think if you log onto the pegasus software it tells you what invoice he is working on right now, then just count to see how many he is away from your invoice.
Lemme check and see if it does that.
--EDIT--
I just checked and it will show you what invoice he is on, but I was too lazy to go to my truck, disconnect the gryphon, come back inside plug it in and then repeat the process in reverse. But your welcome to and then you will have your answer...
