condition mean min max ZT0-3 5.389530000000001 5.389530000000001 5.389530000000001 ZT4-7 4.237045 4.237045 4.237045 ZT8-11 4.252505 4.252505 4.252505 ZT12-15 4.3724 4.3724 4.3724 ZT16-19 6.182869999999999 6.182869999999999 6.182869999999999 ZT20-23 5.279755 5.279755 5.279755