There are a couple of different ways. There is a statutory requirement for the minister to report on the exchange fund account, on the management of Canada's official international reserves, on an annual basis. It's a document that's tabled in Parliament, typically in October, for the previous fiscal year. In addition to that, Canada adheres to IMF reporting standards, which require us to report monthly the position of the exchange fund account five days after the closing of the month.
On May 8th, 2018. See this statement in context.