Hi folks - sorry to bump an old thread but I hope you didn't think I'd forgotten about this project.
I've been working on this a bit more and I can now say that I have collated 35 years of yearbook statistics, including the latest figures from 2015 in the current yearbook.
The spreadsheets now cover from 1981 to 2015. Also thanks those of you who spotted existing errors and notified me - your corrections should be included. Please feel free to message me if you spot any more, particularly in the years now added for 1981 through to 1987.
Download links to the Excel files are below. If you're unsure what the files are or why there are two, please see the first post in this thread.
As for the future of this project, I know many would like to see data going back to 1974/1975. That is still my original goal, though it was always clear that would take considerable time and effort, which has proven to be the case. For now, I need a bit of a break but I hope to pick this up again some time.