condition mean min max ZT0-3 0.5180325 0.2568765 0.7791885 ZT4-7 6.7970299999999995 6.7970299999999995 6.7970299999999995 ZT8-11 13.65235 13.65235 13.65235 ZT12-15 0 0 0 ZT16-19 1.6324174999999999 1.6324174999999999 1.6324174999999999 ZT20-23 0.923454 0.923454 0.923454