condition mean min max ZT0-3 33.87985 33.87985 33.87985 ZT4-7 28.7015 28.7015 28.7015 ZT8-11 32.6749 32.6749 32.6749 ZT12-15 17.86905 17.86905 17.86905 ZT16-19 35.96155 35.96155 35.96155 ZT20-23 32.5392 32.5392 32.5392