condition mean min max ZT0-3 1.5374985 1.003632 2.071365 ZT4-7 1.75808 1.75808 1.75808 ZT8-11 0.9173069999999999 0.9173069999999999 0.9173069999999999 ZT12-15 0 0 0 ZT16-19 1.34665 1.34665 1.34665 ZT20-23 1.3197185 1.3197185 1.3197185