Did some googling. Was about 700ish Bonanza and Pondersosas (same ownership) in the USA around 1990. By 2001, only 300. Today, only 13 total (Ponderosa and Bonanzas) and 9 or 10 of those 13 are Ponderosas, and only 3 or 4 Bonanzas left in the United States. Don't quote me on those numbers. They are close but might not be exact. I did the search last night.
Lebanon is kind of unique that it's only one out of 3 or 4 Bonanzas left in America regarding what once was, an outstanding steak house. We are getting into "Tastee Freeze" territory here with only about 12 Tastee Freezes left in America. Just rare to find one, much like Lebanons Bonanza.