condition mean min max ZT0-3 7.845188333333334 5.70773 9.150615 ZT4-7 5.1878899999999994 5.1878899999999994 5.1878899999999994 ZT8-11 4.709960000000001 4.709960000000001 4.709960000000001 ZT12-15 6.12922 6.08597 6.172470000000001 ZT16-19 5.69112 5.69112 5.69112 ZT20-23 8.152835 8.152835 8.152835