Many thanks for all your comments. They've been helpful pointers for me, as I'm new to MusicBee.
After a bit of playing with the Configure Layout options, it is apparent that the track count shows up when Panel Layout is set to either "Album and Tracks" or "Track Detail". However, the track count is not available when Panel Layout is set to "Artwork".
It would be useful to have the track count displayed when Panel Layout is set to "Artwork". It just makes for a more complete summary being available for the user. I just prefer to have my panel layout in Album mode, but I'd still like to have all the summary information available to me.
I've also noticed that, when Panel Layout is set to "Album and Tracks" or to "Track Detail", then the total album count is not displayed. It would be handy if the missing information were displayed. I'm not sure why it might have been left out, whether by accident or by design.