condition mean min max ZT0-3 3.8242066666666665 3.543465 4.148375 ZT4-7 2.8712299999999997 2.8712299999999997 2.8712299999999997 ZT8-11 3.2858799999999997 3.2858799999999997 3.2858799999999997 ZT12-15 6.4321649999999995 6.361905 6.502425 ZT16-19 4.51285 4.51285 4.51285 ZT20-23 4.51213 4.51213 4.51213