MAD means Mean Absolute Deviation, in this case you have MAD = 0.
Furthermore, one of the values of the data is 14.
MAD = ∑|x - xi|/n
where x are the values of the data and xi is the mean of the data.
Due to one of the value is positive and that MAD is equal to zero, it is necessary that there are other values in the data with negative values.
Furthermore, it is also possible that THE VALUES IN THE DATA ARE ALL EQUALS.