condition mean min max ZT0-3 939.855241 939.855241 939.855241 ZT4-7 630.444009 630.444009 630.444009 ZT8-11 447.0682025 447.0682025 447.0682025 ZT12-15 1371.614814 1371.614814 1371.614814 ZT16-19 573.2809985 573.2809985 573.2809985 ZT20-23 534.540286 534.540286 534.540286