condition mean min max ZT0-3 3.9648674999999995 3.20811 4.7216249999999995 ZT4-7 3.870265 3.870265 3.870265 ZT8-11 3.568435 3.568435 3.568435 ZT12-15 0 0 0 ZT16-19 6.309835 6.309835 6.309835 ZT20-23 6.34118 6.34118 6.34118