score:3
There are official documents about forced labor here: http://www.bundesarchiv.de/zwangsarbeit/geschichte/auslaendisch/begriffe/index.html.en and http://www.zwangsarbeit-archiv.de/en/index.html
These sources are about forced labor, which is not the same as the number of people brought into concentration camps. The number of 7,6 million is rather the total number of prisoners of war and people in the concentration camps. Forced labor was only a minority part of them.