belt-tightening vs subtraction

belt-tightening

noun
  • A reduction in expenditure, often as a result of financial restrictions. 

adj
  • Causing or involving a reduction in expenditure. 

subtraction

noun
  • The removal of something. 

  • The process of subtracting a number from another. 

  • A calculation involving subtracting. 

How often have the words belt-tightening and subtraction occurred in a corpus of books? (source: Google Ngram Viewer )