condition mean min max ZT0-3 1.51854 1.15836 1.810635 ZT4-7 2.16121 2.16121 2.16121 ZT8-11 2.55304 2.55304 2.55304 ZT12-15 2.1252225 1.56585 2.684595 ZT16-19 2.1412750000000003 2.1412750000000003 2.1412750000000003 ZT20-23 1.9071799999999999 1.9071799999999999 1.9071799999999999