condition mean min max ZT0-3 25.509700000000002 24.6662 26.6946 ZT4-7 21.7734 21.7734 21.7734 ZT8-11 16.712699999999998 16.712699999999998 16.712699999999998 ZT12-15 14.31345 13.74955 14.87735 ZT16-19 14.5039 14.5039 14.5039 ZT20-23 21.1492 21.1492 21.1492