condition mean min max ZT0-3 9.517146 9.517146 9.517146 ZT4-7 10.222347500000001 10.222347500000001 10.222347500000001 ZT8-11 9.1059725 9.1059725 9.1059725 ZT12-15 9.7945055 9.7945055 9.7945055 ZT16-19 8.516289 8.516289 8.516289 ZT20-23 9.0910965 9.0910965 9.0910965