condition mean min max ZT0-3 8.446746 8.446746 8.446746 ZT4-7 7.998072499999999 7.998072499999999 7.998072499999999 ZT8-11 8.772185499999999 8.772185499999999 8.772185499999999 ZT12-15 7.996962 7.996962 7.996962 ZT16-19 7.69471 7.69471 7.69471 ZT20-23 8.504729000000001 8.504729000000001 8.504729000000001