condition mean min max ZT0-3 23.91461 23.91461 23.91461 ZT4-7 20.908313999999997 20.908313999999997 20.908313999999997 ZT8-11 17.318923499999997 17.318923499999997 17.318923499999997 ZT12-15 19.9431665 19.9431665 19.9431665 ZT16-19 18.468121 18.468121 18.468121 ZT20-23 18.6141485 18.6141485 18.6141485