Barring a few exceptions,[lower-alpha 5] most countries in the world allow civilians to purchase firearms subject to certain restrictions.[13] A 2011 survey of 28 countries over five continents[lower-alpha 6] found that a major distinction between different national regimes of firearm regulation is whether civilian gun ownership is seen as a right or a privilege.[16] The study concluded that both the United States and Yemen were distinct from the other countries surveyed in viewing firearm ownership as a basic right of civilians and in having more permissive regimes of civilian gun ownership.[16] In the remaining countries included in the sample, civilian firearm ownership is considered a privilege and the legislation governing possession of firearms is correspondingly more restrictive.[16]