Jehovah`s Witnesses do not preach to Muslims the followers of Islam in their own lands under Islamic rule on pain of death .
So approximately half of the worlds population have never been witnessed to in the 100+ years of Jehovah`s Witnesses preaching the "Good news of The Kingdom"
In other words Jehovah`s Witnesses have failed to complete / fulfill the prophecy that
"This Good news Will Be Preached In All The Inhabited Earth " before the end comes .
They have only half completed it in 100 + YEARS of witnessing.