In this section, “examiner” means: The Commissioner; and An individual whom the Commissioner designates as examiner. An examiner shall visit each credit union and examine its business: At least once during each calendar year, unless the Commissioner determines that, during a calendar year, an examination is unnecessary, in which event an examination shall occur no less frequently than once every 18 months; When requested by the board or supervisory committee of the credit union; and At any other time that the Commissioner considers necessary.