This entry isn't about a single prophecy, but rather a series of individual prophecies covering judgments, war, famine, plagues and other events that will happen both during the Tribulation and the Pre-Tribulation period, starting from approximately around the time of the Rapture forward to the second coming in which a massive amount of death and world depopulation occurs.  At the start of this period the world population will potentially be as high as 7.5 billion.  By the time of the second coming, when this will all end, there will be less than 500 million people left on Earth, possibly as few as a hundred million, a reduction of up to 98% of the Earth's population that existed at the time of the rapture.  But at the absolute most, no more than 10% of those alive at the time of the rapture will still remain at the end.

EDIT (2022-01-12): Setting this back to pending as we're nowhere near even really starting this fulfillment at the present time, even though there are initial movements in that direction right now.  However, I don't feel it's enough to justify this prophecy being in the "in progress" state as 99% of this prophecy will be centered in the Tribulation.