I just found out about the hair among the Yao people living in rural China

The women can grow their hair 2.5 meters long and I never was aware that a human can grow hair that long. They never  cut their hair. They keep it in a bun and take it out of the bun for periodic washing.

I have written about this before here:  https://baldingblog.com/2006/09/28/rapunzel-let-down-your-long-golden-hair/ and at that time I focused on the long hair of my grandmother which was really dreads, not real hair length. I have seen some women who have let their hair grow down to reach their upper thigh, but that length is not 2.5 meters, rather a little over a meter.

This population must have a mutan gene that keeps the anagen cycle (growth hair cycle) growing for more than 10 years. Do the math, if hair grows at a rate of 1/2 inch per month, how long does it take to get hair that is 2.5 meters long?