I hope by each tme you mean from several tries at the same time/day, not each time you measure weekly or months

The tables in PP are a reproduction from "the complete book of physical fitness" which are often sited by other books to estimate body fat.

However, it is possible for people to lose weight, and yet maintain the same body fat ratio Which implies a loss of both muscles and fat, due to several factors, including lack of activity and/or undereating.

Wa'il