condition mean min max ZT0-3 2.089968333333333 1.75759 2.353465 ZT4-7 1.68589 1.68589 1.68589 ZT8-11 1.691805 1.691805 1.691805 ZT12-15 3.18084 2.9374700000000002 3.42421 ZT16-19 2.96363 2.96363 2.96363 ZT20-23 2.898505 2.898505 2.898505