condition mean min max ZT0-3 1.600955 1.600955 1.600955 ZT4-7 1.983165 1.983165 1.983165 ZT8-11 4.14217 4.14217 4.14217 ZT12-15 5.27746 5.27746 5.27746 ZT16-19 5.32939 5.32939 5.32939 ZT20-23 1.51987 1.51987 1.51987