condition mean min max ZT0-3 5.767155 5.767155 5.767155 ZT4-7 3.427125 3.427125 3.427125 ZT8-11 3.681985 3.681985 3.681985 ZT12-15 4.293725 4.293725 4.293725 ZT16-19 6.659 6.659 6.659 ZT20-23 6.41414 6.41414 6.41414