Trying to think of an accurate way to access age. Accuracy is an issue when we're talking about such a precise cutoff. Looking around seems to show this is actually a difficult problem for immigration officials:
https://www.newscientist.com/article...determine-age/
The other problem is that people age different as a result of environmental factors as well. Stress, poor nutrition and so on and I imagine a lot of these people will have suffered a lot of that to say the least.