condition mean min max ZT0-3 4.4245600000000005 4.4245600000000005 4.4245600000000005 ZT4-7 4.91736 4.91736 4.91736 ZT8-11 4.7270900000000005 4.7270900000000005 4.7270900000000005 ZT12-15 4.754665 4.754665 4.754665 ZT16-19 4.809363333333333 4.809363333333333 4.809363333333333 ZT20-23 5.3274 5.3274 5.3274