inroad vs resistance

inroad

noun
  • An advance into enemy territory, an attempted invasion; an encroachment, an incursion. 

  • Often followed by in, into, or on: initial progress made toward accomplishing a goal or solving a problem. 

resistance

noun
  • The act of resisting, or the capacity to resist. 

  • An underground organisation engaged in a struggle for liberation from forceful occupation; a resistance movement. 

  • A force that tends to oppose motion. 

  • electrical resistance. 

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