condition mean min max ZT0-3 9.720493 9.720493 9.720493 ZT4-7 9.7828175 9.7828175 9.7828175 ZT8-11 9.3192095 9.3192095 9.3192095 ZT12-15 9.344263 9.344263 9.344263 ZT16-19 9.389276500000001 9.389276500000001 9.389276500000001 ZT20-23 9.297937000000001 9.297937000000001 9.297937000000001