condition mean min max ZT0-3 3.1696150000000003 2.523225 3.7174750000000003 ZT4-7 3.559315 3.559315 3.559315 ZT8-11 3.178935 3.178935 3.178935 ZT12-15 5.2878775000000005 5.17574 5.400015 ZT16-19 4.15369 4.15369 4.15369 ZT20-23 6.2991399999999995 6.2991399999999995 6.2991399999999995