condition mean min max ZT0-3 1.9329383333333334 1.35761 2.53546 ZT4-7 1.3779599999999999 1.3779599999999999 1.3779599999999999 ZT8-11 1.9537550000000001 1.9537550000000001 1.9537550000000001 ZT12-15 5.4697474999999995 5.0292449999999995 5.91025 ZT16-19 5.320444999999999 5.320444999999999 5.320444999999999 ZT20-23 3.891555 3.891555 3.891555