condition mean min max ZT0-3 2.10394 2.10394 2.10394 ZT4-7 1.53165 1.53165 1.53165 ZT8-11 2.192875 2.192875 2.192875 ZT12-15 2.67891 2.67891 2.67891 ZT16-19 3.23681 3.23681 3.23681 ZT20-23 4.536355 4.536355 4.536355