condition mean min max ZT0-3 5.152093333333333 4.598755 5.78798 ZT4-7 3.30044 3.30044 3.30044 ZT8-11 4.51778 4.51778 4.51778 ZT12-15 13.647825 13.535699999999999 13.75995 ZT16-19 7.809385 7.809385 7.809385 ZT20-23 8.28223 8.28223 8.28223