condition mean min max ZT0-3 15.63175 14.9169 16.346600000000002 ZT4-7 18.68595 18.68595 18.68595 ZT8-11 14.4717 14.4717 14.4717 ZT12-15 0 0 0 ZT16-19 24.365000000000002 24.365000000000002 24.365000000000002 ZT20-23 19.4759 19.4759 19.4759