The terms and conditions of pooling provide that the size of an eligible group is determined by the number of certificates in effect in Canada on December 31 of the year in question, even though only Quebec certificates are subject to pooling.
The number of certificates for a group that ends during the year is determined by taking the average of the number of certificates in effect on December 31 of the previous year (or the date the group came into effect, if it was during the year in question) and those in effect at the time the plan ended.
The average used is a simple arithmetic average, without weighting.