199.1. Where several partial terminations have occurred in respect of the same pension plan, or where, in a given period and on different dates, several events have occurred which could each result in a partial termination of the plan, those terminations or events may, for the purposes of this chapter, be considered to be or to relate to one and the same partial termination if, in the opinion of the Régie, they are based on similar circumstances, such as those mentioned in section 165.1.