condition mean min max ZT0-3 8.176843333333334 4.37378 10.755600000000001 ZT4-7 3.733165 3.733165 3.733165 ZT8-11 3.84307 3.84307 3.84307 ZT12-15 5.652912499999999 5.431185 5.874639999999999 ZT16-19 6.915235 6.915235 6.915235 ZT20-23 9.92545 9.92545 9.92545