DR-40 when I delete a track, the track number remains?

[Hamilton]

I hope you can help. I'm quite new but can't find the solution in the manual or online (or by searching this forum), so apologies if this is basic. When I record a track and then delete it, the track number remains - i.e. I'm on track 9, for example, but all of the previous 8 tracks have been deleted. How do you get the track numbers to delete as well, or manually reset to zero. Or are there other solutions. Thanks