condition mean min max ZT0-3 4.746313968500001 4.522446396 4.9701815410000005 ZT4-7 1.9752543405 1.9291740625 2.0213346185 ZT8-11 6.78885614425 4.7323570805 8.845355208 ZT12-15 11.6421750215 10.859151707999999 12.425198335000001 ZT16-19 11.03281898 9.420770025 12.644867935 ZT20-23 18.5505383175 17.262219979999998 19.838856655