date rape vs indecent assault

date rape

noun
  • Rape committed by an acquaintance of the victim while out on a date. 

  • Rape committed after a perpetrator first secretly administers a sedative or memory-inhibiting drug (a date rape drug) to a victim under the cover of a social setting. 

indecent assault

noun
  • Sexual contact with another person, who does not want it, that does not result in, or is not considered to be, rape. 

How often have the words date rape and indecent assault occurred in a corpus of books? (source: Google Ngram Viewer )