condition mean min max ZT0-3 11.074471 11.074471 11.074471 ZT4-7 9.297397 9.297397 9.297397 ZT8-11 8.1491505 8.1491505 8.1491505 ZT12-15 8.9457575 8.9457575 8.9457575 ZT16-19 9.038802 9.038802 9.038802 ZT20-23 9.208438000000001 9.208438000000001 9.208438000000001