It was mentioned at the end of this Amnesty International fact sheet (pdf) that it was first published in 1988 then updated, I think there was also a fifth edition in 2015 so maybe there’s an even another new one now. I’m not sure if this is exactly the same source I saw previously, but that could be because of the various revisions.
I’ve done a little digging, I think it might be this book: Roger Hood, The Death Penalty: A World-wide Perspective.
It was mentioned at the end of this Amnesty International fact sheet (pdf) that it was first published in 1988 then updated, I think there was also a fifth edition in 2015 so maybe there’s an even another new one now. I’m not sure if this is exactly the same source I saw previously, but that could be because of the various revisions.
Thank you!