condition mean min max ZT0-3 2.73688 2.099425 3.27578 ZT4-7 2.38035 2.38035 2.38035 ZT8-11 2.50017 2.50017 2.50017 ZT12-15 2.6188325 2.14454 3.0931249999999997 ZT16-19 2.09395 2.09395 2.09395 ZT20-23 2.7347 2.7347 2.7347