For those candidates who are interested in knowing the total strength of the people who appeared in various types of NAB tests. The answer to how many lies in the structured roll number . For example my roll number is 33120179. When I analyzed this with the exam ID, written on the question booklet (i.e. ID = 12) and then came across with this idea and it proved correct:
33 = City code of Karachi
12 = Deputy Director
0179 = My number in the list of cadidates appearing at an exam center. In my case it is Karachi.

Loaded with this I went through the NTS Candidate Search Option based web page and queried through the last four digit numbers and found out that there were 319 Deputy Director Candidates registered for the Karachi alone. When applied this approach and the normal search I found out that there were four centers in the province of Sindh and I think there were 431 Deputy Director candidates were registered at these four exam centers.

How about my chances, Mr. Arthur? (57 correct for DD)