condition mean min max ZT0-3 5.033916666666667 0.0 8.85665 ZT4-7 0.0 0.0 0.0 ZT8-11 4.0417749999999995 4.0417749999999995 4.0417749999999995 ZT12-15 3.361845 2.437545 4.286145 ZT16-19 2.47854 2.47854 2.47854 ZT20-23 9.3292 9.3292 9.3292