cramp someone's style vs keep back

cramp someone's style

verb
  • To restrict someone's free action or expression. 

keep back

verb
  • To restrict or restrain. 

  • To hold back; to refuse to give or share. 

  • To prevent (a pupil) from advancing in a course. 

  • To stay back; to refrain from approaching. 

How often have the words cramp someone's style and keep back occurred in a corpus of books? (source: Google Ngram Viewer )