condition mean min max ZT0-3 4.89673 2.737805 6.028335 ZT4-7 2.197865 2.197865 2.197865 ZT8-11 2.24878 2.24878 2.24878 ZT12-15 4.144635 3.284845 5.004425 ZT16-19 5.361655000000001 5.361655000000001 5.361655000000001 ZT20-23 7.835255 7.835255 7.835255