(a) There shall be empaneled in every county having less than 50,000 population not less than two grand juries in every year; and, when they have completed their labors, in its discretion, the court may permit them to take a recess subject to the call of the judge of the circuit court or Chief Justice of the Supreme Court, and they may be reassembled at any place where the circuit court of the county is to be held.
(b) In all counties having over 50,000 population, there shall be empaneled not less than four grand juries in every year.