condition mean min max ZT0-3 16.996163333333335 5.78534 22.70275 ZT4-7 5.588585 5.588585 5.588585 ZT8-11 2.62221 2.62221 2.62221 ZT12-15 7.845092500000001 7.2133400000000005 8.476845 ZT16-19 8.011519999999999 8.011519999999999 8.011519999999999 ZT20-23 12.927875 12.927875 12.927875