There are two compilations in the Historical Compilations folder. The first spreadsheet has all of the Program Handbook trips, trip leaders and member counts since 1912. This data is also on the Trip page where it is accompanied by more detailed information.
The second spreadsheet is a list of speakers at member meeting and Wildlife Series meetings. The current edition has everything since 1980 plus 1955. Perhaps earlier dates will be added at some point in the future.