In 1999 a charter challenge against the residency requirement was rejected because the detrimental effects of the 10-year residency requirement did not “comprise a category analogous to those described” in section 15 of the charter; section 15 of the charter identifies a specific set of discriminatory criteria that warrants the court's specific attention, but it does not mean that discrimination or hardship doesn't exist because it isn't included on this list.
On May 13th, 2008. See this statement in context.