condition mean min max ZT0-3 4.659681666666667 3.7625349999999997 6.450545 ZT4-7 4.64043 4.64043 4.64043 ZT8-11 3.66833 3.66833 3.66833 ZT12-15 4.972165 4.913625 5.030705 ZT16-19 5.619585000000001 5.619585000000001 5.619585000000001 ZT20-23 5.13196 5.13196 5.13196