condition mean min max ZT0-3 34.7916 34.7916 34.7916 ZT4-7 33.665949999999995 33.665949999999995 33.665949999999995 ZT8-11 19.910249999999998 19.910249999999998 19.910249999999998 ZT12-15 20.7198 20.7198 20.7198 ZT16-19 21.070149999999998 21.070149999999998 21.070149999999998 ZT20-23 28.89425 28.89425 28.89425