condition mean min max ZT0-3 2.3990625 2.06539 2.732735 ZT4-7 0.8647404999999999 0.8647404999999999 0.8647404999999999 ZT8-11 2.77125 2.77125 2.77125 ZT12-15 0 0 0 ZT16-19 1.0153349999999999 1.0153349999999999 1.0153349999999999 ZT20-23 2.893415 2.893415 2.893415