crazy like a fox vs streetwise

crazy like a fox

adj
  • Behaving in a foolish, frivolous, or uncomprehending manner as a ruse for concealing clever deeds or deeper intentions. 

streetwise

adj
  • Having the necessary knack, personality and instinct for survival in rough, urban environments. 

  • Possessing a style that embodies the life and microculture located within urban settings, typically in the States. 

How often have the words crazy like a fox and streetwise occurred in a corpus of books? (source: Google Ngram Viewer )