condition mean min max ZT0-3 280.919903 280.919903 280.919903 ZT4-7 271.6837255 271.6837255 271.6837255 ZT8-11 291.5141695 291.5141695 291.5141695 ZT12-15 251.2793555 251.2793555 251.2793555 ZT16-19 283.5575785 283.5575785 283.5575785 ZT20-23 271.027185 271.027185 271.027185