condition mean min max ZT0-3 1.810905 1.810905 1.810905 ZT4-7 1.649165 1.649165 1.649165 ZT8-11 1.8018 1.8018 1.8018 ZT12-15 2.79511 2.79511 2.79511 ZT16-19 1.53884 1.53884 1.53884 ZT20-23 1.929915 1.929915 1.929915