There were on average 607 000 people in prison in the 27 European Union member states between 2005 and 2007, equivalent to about 123 prisoners for every 100 000 residents of the bloc, EU statistics office Eurostat said on June 19 2009.

During that time, Bulgaria had 11 400 people in jail in 2005, 11 450 in 2006 and 10 790 in 2007, an average of 145 out of 100 000.

Separate statistics from January 2008 said that the United States, which has a population of about 304 million people, had 2.3 million people in jail. This is in spite of the EU having a larger population, currently estimated at 449.7 million.

Eurostat’s figures for the US were different. It gave a rate of 758 prisoners for every 100 000 inhabitants in the US over the same period.
A statement on June 19 by the European Commission said that the political and social sensitivity of issues of crime and criminal justice, together with growing public concern, had made it increasingly important to obtain a view of the situation in the EU.

Eurostat, in partnership with the statistical authorities of the EU member states and the European Commission’s Directorate-General for Justice, Freedom and Security, is developing a more comparable system of crime and criminal justice statistics, the EC said.

"However, measuring tendencies in crime in the EU remains a difficult task, due to the differences in the data collection sources," the EC said.

Eurostat said that any attempt to measure the extent of crime in Europe is complicated by the fact that countries have widely differing methods of recording offences.

Most of the data are taken from information recorded or reported by the police.

Comparisons of crime levels based on the absolute figures would be misleading, since they are affected by many factors, including different legal and criminal justice systems; rates at which crimes are reported to the police and recorded by them; differences in the point at which crime is measured (for example, report to the police, identification of suspect, etc); differences in the rules by which multiple offences are counted; and differences in the list of offences that are included in the overall crime figures.
 
The EC said that the figures released on June 19 were taken from a recent report by Eurostat , since they are among the most comparable crime indicators among member states .

The highest average prisoner rates over the period 2005 to 2007 were recorded in Estonia (302  prisoners per 100 000 inhabitants ), Latvia (293), Lithuania (232), Poland (228) and the Czech Republic (185).

The lowest rates were registered in Slovenia (60), Finland (68), Denmark (71), Ireland (75 in 2004-2006) and Sweden (77).