condition mean min max ZT0-3 13.844453 13.844453 13.844453 ZT4-7 15.825147 15.825147 15.825147 ZT8-11 15.9159 15.9159 15.9159 ZT12-15 14.468931 14.468931 14.468931 ZT16-19 14.5197465 14.5197465 14.5197465 ZT20-23 14.681255499999999 14.681255499999999 14.681255499999999