condition mean min max ZT0-3 3.41657 3.41657 3.41657 ZT4-7 7.042395 7.042395 7.042395 ZT8-11 1.91445 1.91445 1.91445 ZT12-15 0.747093 0.747093 0.747093 ZT16-19 0.6256174999999999 0.6256174999999999 0.6256174999999999 ZT20-23 2.21701 2.21701 2.21701