News from North Korea

The report points out that 1% of the population is in the massive labor camps and between 5 and 10% of those in the camps do not survive their stay. How does that compare to the US? We do have a large percentage of our population in prison and prison is a very dangerous place. Also, with mandatory sentencing laws there are more and more prisoners dying of old age so that, along with the violence of prison life, might bring the percentage of those who do not survive their stay up to the 1% range I would imagine, though I would be shocked if it was anywhere near 5%. Anyone have any figures on this?