condition mean min max ZT0-3 23.20405 22.3812 24.026899999999998 ZT4-7 27.67425 27.67425 27.67425 ZT8-11 29.81955 29.81955 29.81955 ZT12-15 0 0 0 ZT16-19 38.37165 38.37165 38.37165 ZT20-23 31.07925 31.07925 31.07925