Four Enders In A Loomis Box. How Many More Silver Coins Did I Find?

Today I picked up the two $500 Loomis boxes that I asked a bank manager to order two weeks ago after I found part of a collection dump -- including five Walking Liberty half dollars -- in a partial box that the bank already had on hand. One box contained no silver coins (the usual outcome). But I found four enders(!) in the other box (including a 1964 Kennedy half dollar). From a statistical perspective (finding four silver coins out of 100 total enders I had examined), I anticipated that I reasonably should expect to find ~40 silver coins in this box.

I eventually found five 90% silver Kennedy half dollars and 36 40% silver half dollars: i.e., 7.1+ troy ounces of silver (one of my best CRH results). Most rolls in this box contained one silver coin, but two rolls each contained three silver coins. I also found two proof half dollars. I wonder if these coins are part of the same "dump" that I acquired at this bank two weeks ago?

I've ordered two more Loomis boxes from the bank.