condition mean min max ZT0-3 6.985815 6.28632 7.685309999999999 ZT4-7 5.508405 5.508405 5.508405 ZT8-11 5.06698 5.06698 5.06698 ZT12-15 0 0 0 ZT16-19 8.63577 8.63577 8.63577 ZT20-23 7.808755 7.808755 7.808755