condition mean min max ZT0-3 0.686884 0.686884 0.686884 ZT4-7 1.050665 1.050665 1.050665 ZT8-11 1.267533 1.267533 1.267533 ZT12-15 0.41267600000000004 0.41267600000000004 0.41267600000000004 ZT16-19 0.746132 0.746132 0.746132 ZT20-23 0.9934585 0.9934585 0.9934585