perplex vs start in on

perplex

verb
  • To cause to feel baffled; to puzzle. 

  • To involve; to entangle; to make intricate or complicated. 

start in on

verb
  • To attack verbally or physically. 

  • To make a start on; to begin to tackle. 

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