An indictment cannot be found without concurrence of at least 14 grand jurors in a county in which the required number of members of the grand jury prescribed by Section 888.2 is 23, at least eight grand jurors in a county in which the required number of members is 11, and at least 12 grand jurors in all other counties. When so found it shall be endorsed, “A true bill,” and the endorsement shall be signed by the foreman of the grand jury.