The Department of State Police in addition to the superintendent, the deputy superintendent and the executive officer shall consist of:
a. A headquarters staff and three troops.
b. Officers and men, the number of each grade of which shall be substantially as follows:
One captain inspector; four captains; thirteen lieutenants; two staff sergeants; four first sergeants; thirty sergeants; twenty corporals; ten first-class detectives; twenty second-class detectives and two hundred and eighty troopers.