Is there a reasonable explanation as to why I found Jet in Vault 92 (not sure on the actual number)? To my knowledge Jet was invented by a teenager in Fallout 2. I can buy Jet being in the CW via trade, smuggling, and BOS possibly bringing it with them but there's no explanation I can think of for it to be in a vault.

The Vault was open to the wasteland. Someone with Jet went into the vault and left it there. All the vaults in DC have opened at some point.

Good enough of an explanation?