Sorry, yes, my meaning was that it seems as though the number OP used to arrive at the conclusion is incorrect, either because OP made an error, or because of s

Sorry, yes, my meaning was that it seems as though the number OP used to arrive at the conclusion is incorrect, either because OP made an error, or because of some reason that leads folks to under-report (as you suggest above), or because the data is wrong for some other reason.