condition mean min max ZT0-3 8.41171 7.422855 9.400565 ZT4-7 7.366585 7.366585 7.366585 ZT8-11 5.802125 5.802125 5.802125 ZT12-15 0 0 0 ZT16-19 7.812385 7.812385 7.812385 ZT20-23 9.512935 9.512935 9.512935