condition mean min max ZT0-3 2.6864825000000003 2.053715 3.3192500000000003 ZT4-7 1.797515 1.797515 1.797515 ZT8-11 2.08491 2.08491 2.08491 ZT12-15 0 0 0 ZT16-19 2.4898800000000003 2.4898800000000003 2.4898800000000003 ZT20-23 3.448595 3.448595 3.448595