Because violence against women and children doesn’t count

Here’s a disturbing story. The first-ever Global Peace Index has been published by the Economist Intelligence Unit, measuring nations by their peacefulness and ranking them by their “absence of violence.”
Unfortunately, that “absence of violence” doesn’t seem to count for women and children. The Christian Science Monitor reports that the index fails to include this sadly prevalent form of violence and gives high ranks to countries with poor records on women’s and children’s rights.
Why am I not surprised?