condition mean min max ZT0-3 203.546856 203.546856 203.546856 ZT4-7 150.9675295 150.9675295 150.9675295 ZT8-11 240.586546 240.586546 240.586546 ZT12-15 270.5080275 270.5080275 270.5080275 ZT16-19 378.722959 378.722959 378.722959 ZT20-23 437.898487 437.898487 437.898487