condition mean min max ZT0-3 5.22549 5.22549 5.22549 ZT4-7 5.303403333333333 5.303403333333333 5.303403333333333 ZT8-11 3.10591 3.10591 3.10591 ZT12-15 4.3138000000000005 4.3138000000000005 4.3138000000000005 ZT16-19 3.572003 3.572003 3.572003 ZT20-23 1.2375099999999999 1.2375099999999999 1.2375099999999999