condition mean min max ZT0-3 18.416964735 17.1239623 19.70996717 ZT4-7 13.428010517499999 11.659990155 15.196030879999999 ZT8-11 13.148386769999998 12.82937185 13.467401689999999 ZT12-15 14.044720295000001 12.200564620000002 15.888875969999999 ZT16-19 32.0114179575 22.255979054999997 41.766856860000004 ZT20-23 76.847256735 68.09010081 85.60441266000001