condition mean min max ZT0-3 5.795453333333334 5.17054 6.14626 ZT4-7 5.589475 5.589475 5.589475 ZT8-11 4.30858 4.30858 4.30858 ZT12-15 5.61558 5.038965 6.192195 ZT16-19 6.5746199999999995 6.5746199999999995 6.5746199999999995 ZT20-23 7.8122549999999995 7.8122549999999995 7.8122549999999995