condition mean min max ZT0-3 22.089414 22.089414 22.089414 ZT4-7 25.747322500000003 25.747322500000003 25.747322500000003 ZT8-11 21.981268 21.981268 21.981268 ZT12-15 28.7924275 28.7924275 28.7924275 ZT16-19 31.2016665 31.2016665 31.2016665 ZT20-23 35.676376 35.676376 35.676376