condition mean min max ZT0-3 2.343793333333333 1.8752 3.2478 ZT4-7 1.91818 1.91818 1.91818 ZT8-11 1.932985 1.932985 1.932985 ZT12-15 5.70018 5.658939999999999 5.74142 ZT16-19 6.594425 6.594425 6.594425 ZT20-23 3.93775 3.93775 3.93775