complexify vs snarl up

complexify

verb
  • To make something more complex; to complicate. 

snarl up

verb
  • To put into disarray; contort; confuse; muddle up 

  • to become congested. 

  • To become tangled; to become entangled 

  • to entangle 

  • To block (traffic); to cause (traffic) to be congested. 

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