condition mean min max ZT0-3 9.3019675 8.61457 9.989365 ZT4-7 8.090875 8.090875 8.090875 ZT8-11 17.8535 17.8535 17.8535 ZT12-15 0 0 0 ZT16-19 17.8121 17.8121 17.8121 ZT20-23 12.264199999999999 12.264199999999999 12.264199999999999