They did an updated version that came out in 2015 for the 40th season. So that explains where I read it.
I also really recommend the book Live From New York, it's made up almost entirely of first hand accounts from the creators, cast members, writers, and hosts of the show over the 40 year run
This book was where I read it.
I would recommend this book for all the answers you wanted and more
https://www.amazon.com/Live-New-York-Complete-Uncensored/dp/031629506X
Live from New York, by Tom Shales Fun stuff.