condition mean min max ZT0-3 6.094165 6.094165 6.094165 ZT4-7 3.88218 3.88218 3.88218 ZT8-11 3.943715 3.943715 3.943715 ZT12-15 4.504334999999999 4.504334999999999 4.504334999999999 ZT16-19 7.66958 7.66958 7.66958 ZT20-23 6.65146 6.65146 6.65146