condition mean min max ZT0-3 637.770518 637.770518 637.770518 ZT4-7 284.025424 284.025424 284.025424 ZT8-11 234.77051849999998 234.77051849999998 234.77051849999998 ZT12-15 358.4438435 358.4438435 358.4438435 ZT16-19 331.18778499999996 331.18778499999996 331.18778499999996 ZT20-23 160.838969 160.838969 160.838969