In the United States, 57 percent of wallets with money were given back.
I would hope they did enough sampling. Similarly: Was it Mexico City or Queretaro? Was it Istanbul or Ephesus? etc
Not useless at all - the real intent is to have folks carry more cash so others can rob them and actually get something for their efforts - the “if you lose it” meme was just to increase the efficacy of the desire...