http://www.democraticunderground.com/10021997746
and here's some data from it, including the factoid about costa rica:
The key facts are:
The US has the highest gun ownership rate in the world - an average of 88 per 100 people. That puts it first in the world for gun ownership - and even the number two country, Yemen, has significantly fewer - 54.8 per 100 people
But the US does not have the worst firearm murder rate - that prize belongs to Honduras, El Salvador and Jamaica. In fact, the US is number 28, with a rate of 2.97 per 100,000 people.
Puerto Rico tops the world's table for firearms murders as a percentage of all homicides - 94.8%. It's followed by Sierra Leone in Africa and Saint Kitts and Nevis in the Caribbean.
http://www.guardian.co.uk/news/datablog/2012/jul/22/gun-homicides-ownership-world-list
Countries with higher murder by gun rates than the US & lower rates of gun ownership:
gun murders/100,000 + guns/100
(US = 2.97/100,000 + 88/100)
Argentina: 3.02/100,000
10.2/100
Bahamas: 15.2/100,000
5.3/100
Barbados: 2.99/100,000
7.8/100
Belize: 21.82/100,000
10/100
Brazil: 18.1/100,000
8/100
Colombia: 27.9/100,000
5.9/100
Costa Rica: 4.59/100,000
9.9/100
Dominican Republic: 16.3/100,000
5.1/100
Ecuador: 12.73/100,000
1.3/100
etc....
The Small Arms Survey is an independent research project located at the Graduate Institute of International and Development Studies in Geneva, Switzerland. It provides impartial and public information on all aspects of small arms and light weapons, as a resource for governments, policy-makers, researchers, and activists, as well as research on small arms issues.
The Survey monitors national and international initiatives (governmental and non-governmental), and acts as a forum and clearinghouse for the sharing of information. It also disseminates best practice measures and initiatives dealing with small arms issues.
The Small Arms Survey mandate is to look at all aspects of small arms and armed violence. It provides research and analysis to support Governments to reduce the incidence of armed violence and illicit trafficking through our evidence-based analysis.
http://en.wikipedia.org/wiki/Small_Arms_Survey