Yes, we do have statistics that indicate every time exemptions were granted. Most of the time, they are granted when personal information or information regarding international affairs or national defence are concerned, or in the case of a strengthening of the legislation or investigations. In reality, most of the time, it serves to ensure confidentiality of information related to one person or to national defence, or in other situations, of information pertaining to the strengthening of the legislation.
On October 18th, 2017. See this statement in context.