condition mean min max ZT0-3 19.868399999999998 17.712699999999998 22.024099999999997 ZT4-7 13.8692 13.8692 13.8692 ZT8-11 17.47115 17.47115 17.47115 ZT12-15 0 0 0 ZT16-19 22.322049999999997 22.322049999999997 22.322049999999997 ZT20-23 20.57815 20.57815 20.57815