condition mean min max ZT0-3 3.8230375 2.859575 4.7865 ZT4-7 5.559635 5.559635 5.559635 ZT8-11 4.459239999999999 4.459239999999999 4.459239999999999 ZT12-15 0 0 0 ZT16-19 8.329509999999999 8.329509999999999 8.329509999999999 ZT20-23 7.11567 7.11567 7.11567