condition mean min max ZT0-3 2.704238333333333 1.728195 3.8027699999999998 ZT4-7 1.285988 1.285988 1.285988 ZT8-11 4.58454 4.58454 4.58454 ZT12-15 3.4865199999999996 2.7519299999999998 4.2211099999999995 ZT16-19 3.6320050000000004 3.6320050000000004 3.6320050000000004 ZT20-23 4.727815 4.727815 4.727815