I question whether they ever actually kept track. Not likely they could track it all. So what's his real motive for this sudden announcement that some are "missing"? As another poster pointed out, this isn't the kind of thing that's usually announced (for obvious reasons). Obama's bureau of disinformation is "leaking" again. What's his angle this time?
Deflection or subject change. I have a "funny" feeling something big is about to surface from the entire Middle East failure and it may not even involve Israel directly. As if the compromised intelligence and deaths weren't enough in Benghazi.