accumulate vs round up

accumulate

verb
  • To heap up in a mass; to pile up; to collect or bring together (either literally or figuratively) 

  • To gradually grow or increase in quantity or number. 

adj
  • Collected; accumulated. 

round up

verb
  • To collect or gather (something) together. 

  • To gather (cattle) together by riding around them. 

  • To round (a number) to the smallest integer that is not less than it, or to some other greater value, especially a whole number of hundreds, thousands, etc. 

  • To arrest or detain a group of people without individualized suspicion or cause, often as a form of targeted persecution. 

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