condition mean min max ZT0-3 7.607117499999999 7.37869 7.835545 ZT4-7 8.75584 8.75584 8.75584 ZT8-11 6.70412 6.70412 6.70412 ZT12-15 0 0 0 ZT16-19 8.655185 8.655185 8.655185 ZT20-23 10.709 10.709 10.709