Around the world, people are still getting away with murder. Indeed, among the three worst-ranking countries for anti-press violence, all showed no improvement, and some even worsened, according to the just-released 2011 Committee to Protect Journalists’ Impunity Index.

For those who aren’t familiar, the index calculates unsolved journalist murders as a percentage of each country’s population. The worst country, Iraq, for example, has 2.921 unsolved journalist murders per 1 million people. That puts it at an impunity rating of three times worse than any other nation, ranking it first (when it comes to who’s worst) for the fourth year in a row.

“Although crossfire and other conflict-related deaths have dropped in Iraq in recent years,” reads the report, “the targeted killings of journalists spike in 2010.”

The Impunity Index was first published in 2008; it only ranks countries where five or more unsolved journalist murders between January 2001 and December 2010. Cases are considered unsolved when there aren’t any convictions. Thirteen nations made the list this year.

“Impunity is a key indicator in assessing levels of press freedom and free expression in nations worldwide,” explains the report, “CPJ research shows that deadly, unpunished violence against journalists often leads to vast self-censorship in the rest of the press corps.”

So, are there any nations actually improving?

Well, some are trying.

In Mexico, the president’s administration adopted broad reforms, including beefing up prosecutor’s office for crimes against free expression, but, unfortunately, the system itself is so corrupt prosecutors can’t seem to win any convictions.

In the Philippines, the country’s president has sworn to prosecute those involved in a 2009 massacre of dozens of journalists (and others), but the trial proceedings to date have been severely hampered by both threats and bribes of witnesses.

Among all the countries, Russia has actually made the most progress. Top investigative officials re-opened several cold cases (after meeting with a CPJ delegation) and later won convictions in the 2009 murder of a Moscow reporter.

For a full summary of each country’s ranking, you can read the report on the CPJ website.