condition mean min max ZT0-3 1.8684874999999999 1.59599 2.1409849999999997 ZT4-7 2.275615 2.275615 2.275615 ZT8-11 2.92887 2.92887 2.92887 ZT12-15 0 0 0 ZT16-19 3.636515 3.636515 3.636515 ZT20-23 3.84276 3.84276 3.84276