condition mean min max ZT0-3 2.1684633333333334 0.65781 4.63091 ZT4-7 0.287166 0.287166 0.287166 ZT8-11 0.603946 0.603946 0.603946 ZT12-15 4.2545175 1.88592 6.623115 ZT16-19 3.43209 3.43209 3.43209 ZT20-23 3.236375 3.236375 3.236375