condition mean min max ZT0-3 322.452355 322.452355 322.452355 ZT4-7 242.83609 242.83609 242.83609 ZT8-11 252.35782899999998 252.35782899999998 252.35782899999998 ZT12-15 297.5718805 297.5718805 297.5718805 ZT16-19 328.74785299999996 328.74785299999996 328.74785299999996 ZT20-23 363.402836 363.402836 363.402836