the frequency of 0 is 7 because 0 occur 7 times .
Similarly frequency of 1 is 15 because 1 occur 15 times.
Similarly frequency of 2 is 4 because 2 occur 4 times.
Similarly frequency of 3 is 4 because 3 occur 4 times.
Finally frequency 0f 4 and 5 is zero because they do not occur.