Yes, it was only American hostages, American killed and/or American servicemen.
I have seen the information for what this list would be if it included other nationalities and the Americans would “disappear” in the list...
I had a similar list that started with the birth of christ and went up to about AD 1970. and yes...the list was enormous. I had it on a zip disk that I can no longer find. It took me a year to get it together in my spare time starting right after 9-11.