condition mean min max ZT0-3 833.539749 833.539749 833.539749 ZT4-7 801.3092995 801.3092995 801.3092995 ZT8-11 856.4313915 856.4313915 856.4313915 ZT12-15 1016.3629095 1016.3629095 1016.3629095 ZT16-19 876.652926 876.652926 876.652926 ZT20-23 794.4034665 794.4034665 794.4034665