Where are you getting your stats from?
My step-mother has been practising criminal law for thirty years. She now lectures in the field.
An allegation of sexual abuse needs a cool head. The idea that children are incapable of lying is so far removed from real life that I find it fucking amusing that any mother or father would validate it.
Many, many kids in this life are sexually abused. No one could possibly deny it.
But the world we live in, in the UK? Eastenders (which I would never allow my kid to watch in a month on Sundays), and any other media personification of abuse, makes it much easier for confused adolescents to make spurious claims, especially against step-parents.
Fourteen year old kids are not grown ups. They do things for attention in much the same way they did ten years earlier.
This is the fine line the legal eagles must walk. But, as people are professionals in their fields, (and with the odd, traumatic exception), most professionals can separate the wheat from the chaff.