condition mean min max ZT0-3 21.125993 21.125993 21.125993 ZT4-7 15.7814825 15.7814825 15.7814825 ZT8-11 15.856653 15.856653 15.856653 ZT12-15 14.553024 14.553024 14.553024 ZT16-19 14.674182 14.674182 14.674182 ZT20-23 14.8764445 14.8764445 14.8764445