condition mean min max ZT0-3 8.7757 8.7757 8.7757 ZT4-7 5.71441 5.71441 5.71441 ZT8-11 7.2737099999999995 7.2737099999999995 7.2737099999999995 ZT12-15 6.809535 6.809535 6.809535 ZT16-19 14.689 14.689 14.689 ZT20-23 7.57503 7.57503 7.57503