If we say assumed that the world was made from the remains of Ymir about 300 000 years ago (remember this is a completely arbitrary number) and then we assume that he got the ring about 250 000 years ago then 91 310 625 would have passed since then until now. Every nine nights he gets eight new rings that are exactly the same but don't make more rings. That would mean that he would have 81 165 000 rings by now.
What the hell would he do with 81 million rings? It's not like he can give them to the other Gods as a Yuletide present. I could imagine it.
"What did you get from Odin this year Thor?"I guess he could start giving them out to people.
"What do you think Njord?"
"Another ring right?"
"Yep. Did you get your ring this year too?"
"Yep. I wonder if he just does this because he can't be bothered making the attempt to find us something?"