condition mean min max ZT0-3 10.33648 10.33648 10.33648 ZT4-7 14.233915 14.233915 14.233915 ZT8-11 13.4793 13.4793 13.4793 ZT12-15 24.7115 24.7115 24.7115 ZT16-19 23.2531 23.2531 23.2531 ZT20-23 17.7162 17.7162 17.7162