gulag vs sweatbox

gulag

noun
  • A prison camp, especially one used to hold political prisoners. 

  • Also GULAG: the system of all Soviet labour camps and prisons in use, especially during the Stalinist period (1930s–1950s). 

  • A place where, or political system in which, people with dissident views are routinely oppressed. 

verb
  • To compel (someone) into a forced labour camp or a similar place of confinement or exile. 

sweatbox

noun
  • A jail cell. 

  • The review process that takes place in a sweat box. 

  • A small overheated cell or room used for solitary confinement or torture. 

  • A small nightclub packed to capacity where people get hot and sweaty. 

  • Any box or boxlike structure used to induce sweating, such as of hides or tobacco 

  • A compartment in a police van to hold a prisoner being transported. 

  • The room where a scene is reviewed. 

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