We're talking about two different statistics. You're talking about how many murderers claim their victim is missing - and I'd say it's nowhere near 85%m but that's okay.
I'm talking about from the police perspective. From their perspective, when they get called in for a missing person, overwhelmingly they are either found safe or are in other ways not victims of the person who reported them missing. Overwhelmingly, they are found safe within the first day of being missing, and they never make the news because it's a blip that doesn't make the news cycle.
During the police workday, it's very rare for someone to report a loved one missing that they've just murdered. So from that perspective, when a person is reported missing it's best use of police force to search for the victim rather than immediately comb through the house for evidence of a murder. That can wait if it becomes more apparent that the reporter isn't telling the truth. If the person is already deceased, the luminol tests on the walls can wait.
Meanwhile, it may be that a missing person is in danger somewhere and needs to be found, just as the reporter has said.
Instead of following HLN and Oxygen to find out these statistics, you might want to follow the "missing" forum here and see how many "missing" are found that same day.