condition mean min max ZT0-3 0.9602401666666667 0.845278 1.0752030000000001 ZT4-7 0.3761895 0.3761895 0.3761895 ZT8-11 0.922373 0.922373 0.922373 ZT12-15 1.357705 1.139945 1.575465 ZT16-19 1.43963 1.43963 1.43963 ZT20-23 1.56511 1.56511 1.56511