What's your source for the gulag numbers? The wiki lists 18M though the system with a population of 180M, with something like 1.5M deaths. That would seem to indicate a number higher than 1%.
The emergent consensus among scholars is that, of the 14 million prisoners who passed through the Gulag camps and the 4 million prisoners who passed through the Gulag colonies from 1930 to 1953, roughly 1.5 to 1.7 million prisoners perished there or they died soon after they were released.
https://en.m.wikipedia.org/wiki/Gulag