dead asleep vs gassed

dead asleep

adj

  • Sleeping in a deep sleep 

gassed

adj

  • Exhausted 

  • Drunk; intoxicated by alcohol. 

  • In a gaseous state. 

  • Happy 

  • Excited 

  • High; intoxicated by psychoactive drugs. 

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