condition mean min max ZT0-3 3.5654925 2.764855 4.36613 ZT4-7 3.91706 3.91706 3.91706 ZT8-11 2.03486 2.03486 2.03486 ZT12-15 0 0 0 ZT16-19 4.296225 4.296225 4.296225 ZT20-23 4.46766 4.46766 4.46766