Hundreds of journalists are killed, injured or imprisoned in the line of duty each year. Reporting on issues and events in war-torn countries affected by conflict is increasingly dangerous, and the principles of press freedom are often undermined around the world.

The Committee to Protect Journalists, a nonprofit that promotes and defends the rights of journalists, keeps track of obstructions to press freedom globally, including the number of fatalities of members of the media.

See also: The 20 Most Socially Progressive Countries in the World

The following chart, created by Statista with information from the CPJ's database, shows the 10 countries with the most journalist killings over the past decade. These include fatalities with "unclear motives."

The data shows that Iraq has been the most dangerous country for journalists, with 174 total deaths since 2004. However, the situation for reporters in Iraq has significantly improved within the past few years. In March, the CPJ announced that Syria is currently the most dangerous country for journalists, due to its recent uprising.

May 3 marked World Press Freedom Day, an annual commemoration of journalists who have lost their lives, as well as a celebration of press freedom's importance. An international conference around this year's theme, "Media Freedom for a Better Future," will be held at the UNESCO Headquarters in Paris on May 5 and 6.