An order of the ministers responsible for health and social security sets the allocation of seats in each union between the trade union organisations. This distribution is established by proportional representation with the highest average, according to :
1° The number of contributors established by the most recent representativeness survey mentioned in Article L. 162-33 for the professions for which it is available;
2° The number of subscribers of each of the trade union organisations for professions for which no representativeness survey is available.