call up vs convoke

call up

verb
  • To call on the telephone. 

  • To select e.g. to a sports squad. 

  • To summon (someone) to report for military service. 

  • To retrieve from personal or computer memory. 

noun
  • An order to report for military service. 

convoke

verb
  • To call together. 

  • To convene, to cause to assemble for a meeting. 

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