condition mean min max ZT0-3 6.851470000000001 6.851470000000001 6.851470000000001 ZT4-7 5.81346 5.81346 5.81346 ZT8-11 5.87084 5.87084 5.87084 ZT12-15 6.23422 6.23422 6.23422 ZT16-19 6.6926000000000005 6.6926000000000005 6.6926000000000005 ZT20-23 5.862885 5.862885 5.862885