Since the Hull C can't land in atmo while loaded, you're supposed to be going between space stations. Not sure why it's only the 4 main stations, but this graph was put together before the 3 jump point stations went in, and those were specifically added to give Hull C owners some more trading points, so now the points are 7 overall.
I have no idea what the graph shows, haven't tried parsing it, but I thought I'd put it here for reference for tomorrow.
