Except as otherwise provided in § 6-102 of this article and except as otherwise provided under this section, government-owned property is not subject to property tax, if the property: is devoted to a governmental use or purpose; and is owned by: the federal government; the State; a county or a municipal corporation; or an agency or instrumentality of the federal government, the State, a county, or of a municipal corporation. The exemption provided for the property owned by an agency or instrumentality in subsection (a)(2)(iv) of this section applies only to the extent that a law exempts the property.