condition mean min max ZT0-3 1.931545 1.69904 2.16405 ZT4-7 1.264055 1.264055 1.264055 ZT8-11 1.1615250000000001 1.1615250000000001 1.1615250000000001 ZT12-15 0 0 0 ZT16-19 3.340395 3.340395 3.340395 ZT20-23 2.1369249999999997 2.1369249999999997 2.1369249999999997