condition mean min max ZT0-3 4.1603650000000005 4.1603650000000005 4.1603650000000005 ZT4-7 3.1016 3.1016 3.1016 ZT8-11 2.064095 2.064095 2.064095 ZT12-15 2.8891 2.8891 2.8891 ZT16-19 7.58808 7.58808 7.58808 ZT20-23 4.61205 4.61205 4.61205