condition mean min max ZT0-3 18.85 18.85 18.85 ZT4-7 6.0 6.0 6.0 ZT8-11 30.2 30.2 30.2 ZT12-15 18.049999999999997 18.049999999999997 18.049999999999997 ZT16-19 8.149999999999999 8.149999999999999 8.149999999999999 ZT20-23 7.35 7.35 7.35