condition mean min max ZT0-3 6.040039999999999 5.726755 6.353325 ZT4-7 6.235035 6.235035 6.235035 ZT8-11 4.71077 4.71077 4.71077 ZT12-15 0 0 0 ZT16-19 6.16056 6.16056 6.16056 ZT20-23 4.841085 4.841085 4.841085