Stakhanovite vs hard worker

Stakhanovite

noun
  • An extremely productive or hard-working worker, especially in the former USSR, who may earn special rewards; a workaholic. 

adj
  • Pertaining to a Stakhanovite; heroically hard-working. 

hard worker

How often have the words Stakhanovite and hard worker occurred in a corpus of books? (source: Google Ngram Viewer )