condition mean min max ZT0-3 5.934933333333333 3.949025 7.9321649999999995 ZT4-7 3.196475 3.196475 3.196475 ZT8-11 3.030785 3.030785 3.030785 ZT12-15 3.7494225 3.715555 3.78329 ZT16-19 4.54347 4.54347 4.54347 ZT20-23 6.79505 6.79505 6.79505