By @astronomyblog & @LoveGraphs. Stats last updated 10 December 2019.
It seems there may have been at least 706 shows and 2756 listed appearances. With 4 people per show, iPlayer is missing at least 2% of appearances (and probably a similar percent of people). The host/captains/regulars have included Melvyn Bragg (Host × 706).
Total appearances:
Guest appearances i.e. ignoring the host/captains/regulars:
All people:
Guests i.e. ignoring the host/captains/regulars:
Last updated: 2019/12/10