keep one's fingers crossed vs touch wood

keep one's fingers crossed

verb
  • To hope for the best, to show support. 

touch wood

intj
  • Hopefully; said while touching something wooden, to avert superstitious bad luck from what has just been said. 

verb
  • To make contact with wood to avert bad luck, in accordance with a folk practice. 

How often have the words keep one's fingers crossed and touch wood occurred in a corpus of books? (source: Google Ngram Viewer )