condition mean min max ZT0-3 40.143675 39.4025 40.88485 ZT4-7 25.6747 25.6747 25.6747 ZT8-11 13.12565 13.12565 13.12565 ZT12-15 0 0 0 ZT16-19 29.54135 29.54135 29.54135 ZT20-23 42.25125 42.25125 42.25125