condition mean min max ZT0-3 2.221685 1.695395 2.7479750000000003 ZT4-7 1.329345 1.329345 1.329345 ZT8-11 1.228045 1.228045 1.228045 ZT12-15 0 0 0 ZT16-19 1.82385 1.82385 1.82385 ZT20-23 1.8814199999999999 1.8814199999999999 1.8814199999999999