condition mean min max ZT0-3 394.347183 394.347183 394.347183 ZT4-7 372.417151 372.417151 372.417151 ZT8-11 442.78469300000006 442.78469300000006 442.78469300000006 ZT12-15 519.802777 519.802777 519.802777 ZT16-19 431.01682500000004 431.01682500000004 431.01682500000004 ZT20-23 337.818987 337.818987 337.818987