condition mean min max ZT0-3 13.03807236 12.88218352 13.193961199999999 ZT4-7 10.012768000249999 8.928965997999999 11.0965700025 ZT8-11 12.683187367499999 11.572969839999999 13.793404894999998 ZT12-15 14.2792373375 13.883603055 14.674871620000001 ZT16-19 19.673525365 17.39713778 21.949912949999998 ZT20-23 28.930836525 25.327236835 32.534436215