condition mean min max ZT0-3 7.438775 7.438775 7.438775 ZT4-7 5.193855 5.193855 5.193855 ZT8-11 2.586825 2.586825 2.586825 ZT12-15 5.41455 5.41455 5.41455 ZT16-19 18.9775 18.9775 18.9775 ZT20-23 13.175799999999999 13.175799999999999 13.175799999999999