condition mean min max ZT0-3 22.55066 8.72988 30.977899999999998 ZT4-7 6.51836 6.51836 6.51836 ZT8-11 3.43763 3.43763 3.43763 ZT12-15 6.2055925 4.191610000000001 8.219574999999999 ZT16-19 8.987285 8.987285 8.987285 ZT20-23 18.0444 18.0444 18.0444