condition mean min max ZT0-3 2.4205375 2.32131 2.519765 ZT4-7 1.3833335 1.3833335 1.3833335 ZT8-11 1.1736875 1.1736875 1.1736875 ZT12-15 0 0 0 ZT16-19 1.4844819999999999 1.4844819999999999 1.4844819999999999 ZT20-23 1.6083965 1.6083965 1.6083965