condition mean min max ZT0-3 15.194616666666667 5.8749 21.0435 ZT4-7 5.988665 5.988665 5.988665 ZT8-11 6.175535 6.175535 6.175535 ZT12-15 7.8656299999999995 5.941369999999999 9.78989 ZT16-19 12.0473 12.0473 12.0473 ZT20-23 19.2998 19.2998 19.2998