condition mean min max ZT0-3 2.6658796259999997 2.295824215 3.035935037 ZT4-7 4.758090866 4.1537109385 5.3624707935 ZT8-11 15.141604722250001 7.406691134500001 22.87651831 ZT12-15 18.97773468525 15.2564651605 22.69900421 ZT16-19 10.81377469525 9.072041518 12.5555078725 ZT20-23 4.40443703075 4.0511516855 4.757722376