assemble vs call off

assemble

verb
  • To put together. 

  • To translate from assembly language to machine code. 

  • To gather as a group. 

call off

verb
  • To telephone in one's notice of a day's absence from work. 

  • To recall; to cancel or call a halt to. 

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