condition mean min max ZT0-3 2.30097 2.30097 2.30097 ZT4-7 2.217515 2.217515 2.217515 ZT8-11 1.9258549999999999 1.9258549999999999 1.9258549999999999 ZT12-15 2.051505 2.051505 2.051505 ZT16-19 3.14812 3.14812 3.14812 ZT20-23 2.60757 2.60757 2.60757