condition mean min max ZT0-3 2.987845 2.3614699999999997 3.61422 ZT4-7 3.855055 3.855055 3.855055 ZT8-11 3.108535 3.108535 3.108535 ZT12-15 0 0 0 ZT16-19 3.95445 3.95445 3.95445 ZT20-23 4.320164999999999 4.320164999999999 4.320164999999999