condition mean min max ZT0-3 3.3443685 2.9885456089999995 3.7001913909999997 ZT4-7 5.1929456195 3.9093506185 6.4765406205 ZT8-11 7.53879395475 7.0279133835 8.049674526 ZT12-15 4.7444402165 4.516287654 4.972592779 ZT16-19 1.91617877675 1.86513588 1.9672216735 ZT20-23 2.27039142625 2.175088177 2.3656946755