That's a proportional measurement. A small difference in an already small value can result in large proportional differences even when the absolute difference is small. This is sort of like how small towns might see their murder rate skyrocket by 300%, but in reality what happened was that there was one murder last year and three murders the following year.
Nearly all countries have rates of women in tech in a band between 10 and 30%. No country has a majority female tech workforce. The notion that there is a "wild variation" in the rates of women's representation in tech is simply not true.
