condition mean min max ZT0-3 6.8636349999999995 5.77957 7.947699999999999 ZT4-7 8.352835 8.352835 8.352835 ZT8-11 7.11564 7.11564 7.11564 ZT12-15 0 0 0 ZT16-19 9.409355 9.409355 9.409355 ZT20-23 10.6963 10.6963 10.6963