condition mean min max ZT0-3 2.016235 1.9786800000000002 2.0537900000000002 ZT4-7 0.650822 0.650822 0.650822 ZT8-11 0.214256 0.214256 0.214256 ZT12-15 0 0 0 ZT16-19 1.719295 1.719295 1.719295 ZT20-23 3.0304849999999997 3.0304849999999997 3.0304849999999997