condition mean min max ZT0-3 6.650061333333334 0.879294 9.811250000000001 ZT4-7 6.3641950000000005 6.3641950000000005 6.3641950000000005 ZT8-11 2.73653 2.73653 2.73653 ZT12-15 3.366995 1.60219 5.1318 ZT16-19 8.842945 8.842945 8.842945 ZT20-23 9.979434999999999 9.979434999999999 9.979434999999999