condition mean min max ZT0-3 3.340375 3.340375 3.340375 ZT4-7 1.697085 1.697085 1.697085 ZT8-11 2.66523 2.66523 2.66523 ZT12-15 6.019105 6.019105 6.019105 ZT16-19 7.026695 7.026695 7.026695 ZT20-23 3.893795 3.893795 3.893795