condition mean min max ZT0-3 1.3290533333333334 0.601495 1.84742 ZT4-7 1.43583 1.43583 1.43583 ZT8-11 1.2078950000000002 1.2078950000000002 1.2078950000000002 ZT12-15 0.150802 0.0 0.301604 ZT16-19 0.57379 0.57379 0.57379 ZT20-23 0.976785 0.976785 0.976785