condition mean min max ZT0-3 27.1309525025 23.435924385 30.82598062 ZT4-7 34.734404575 30.35670055 39.1121086 ZT8-11 37.23117854 36.26681284 38.19554424 ZT12-15 41.042427931666666 28.399549473333334 53.68530639 ZT16-19 14.30321735 11.988395126666667 16.618039573333334 ZT20-23 8.470900335166668 8.098233619333334 8.843567051