condition mean min max ZT0-3 3.6998724999999997 3.345965 4.05378 ZT4-7 3.83772 3.83772 3.83772 ZT8-11 3.291115 3.291115 3.291115 ZT12-15 0 0 0 ZT16-19 5.713115 5.713115 5.713115 ZT20-23 8.00531 8.00531 8.00531