condition mean min max ZT0-3 2.7744 2.4830550000000002 2.963115 ZT4-7 3.947635 3.947635 3.947635 ZT8-11 4.79284 4.79284 4.79284 ZT12-15 5.3772225 4.125055 6.62939 ZT16-19 4.2200050000000005 4.2200050000000005 4.2200050000000005 ZT20-23 4.030945 4.030945 4.030945