I don’t think there is any possible way that number that could be the case, as it would require that the number of people exceeding 10 years to be equal to those not getting 10 years. There are people who exceed that, but they are basically unicorns. Just try and search for testimonials of people who make it 10 years or more and you will see for yourself.
All that aside, even if we assume a 10 year average is an accurate one, it wouldn’t change the fact that there is no way to predict how long it will work for any given person. Right now, we can’t even predict whether a person will respond or not..