condition mean min max ZT0-3 396.168335 396.168335 396.168335 ZT4-7 337.83930399999997 337.83930399999997 337.83930399999997 ZT8-11 633.2962875000001 633.2962875000001 633.2962875000001 ZT12-15 604.042064 604.042064 604.042064 ZT16-19 721.550544 721.550544 721.550544 ZT20-23 659.4401685 659.4401685 659.4401685