guts vs stalwartness

guts

noun
  • Content, substance. 

  • The center of the field. 

  • Courage; determination. 

  • One's innermost feelings. 

  • The entrails or contents of the abdomen. 

  • The essential, core parts. 

  • The ring in the gambling game two-up in which the spinner operates; the centre. 

verb
  • To show determination or courage (especially in the combination guts out). 

  • To eat greedily. 

stalwartness

noun
  • The state or condition of being stalwart. 

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