USA has the highest ratio of prison

In the USA 2.2 million people in detention
In comparison with other countries, there are relatively few prison inmates in Germany. For every 100,000 inhabitants there are 94 prisoners, according to a study released on Wednesday by German Economy Institute in Cologne based on numbers compiled by the University of London. The average number of prisoners for all the member countries of the Organization for Economic Co-operation and Development (OECD) is 276 prisoners per 100,000 inhabitants.
Among the countries having fewer prisoners than Germany are, according to the study, Greece with 90 prisoners per 100,000 inhabitants, France (85), Sweden (82), Denmark (77) and Finland (75). The lowest ratio was in Japan with 62 prisoners per 100,000 inhabitants. The unquestioned front runner in the number of prisoners is the USA, where numerous private businesses are paid by the state for locking up and exploiting people: out of 100,000 inhabitants, the investigation revealed, there are 737 incarcerated, 500 more than in Poland, the country with the second highest prisoner ratio. Altogether therefore in the USA 2.2 million people sit in detention.
Also, internationally, the extent of utilization of the prisons differs sharply according to the Cologne scientists’ report. German penal institutions have a utilization ratio of 97 per cent. The critical need is dramatic in Greece. There the overcapacity rate of prisons is 179 per cent. Likewise Hungary clearly has more prisoners than detention places with a utilization rate of 140 per cent, Italy* (139 per cent) and Spain (134 per cent). Prisons in the USA are also overcrowded with a 108 per cent utilization rate. The overloading of institutes for detention is also, in the opinion of experts, a cause for outbreaks of violence among the prisoners. Besides, it worsens the conditions for re-socialization of the prisoners.