condition mean min max ZT0-3 8.006155 7.6663 8.34601 ZT4-7 6.94392 6.94392 6.94392 ZT8-11 5.8540399999999995 5.8540399999999995 5.8540399999999995 ZT12-15 0 0 0 ZT16-19 6.750635 6.750635 6.750635 ZT20-23 8.10447 8.10447 8.10447