13. An advocate who represents two or more persons charged with the same offence or with a like offence arising from the same course of events and for which the proceedings are held in the same court at or about the same time is entitled to the remuneration applicable to a mandate, increased by the following percentage according to the number of persons represented:
(1) two persons: 50%;
(2) three persons: 100%;
(3) four persons: 150%;
(4) five persons or more: 200%.