expressis verbis vs obviously

expressis verbis

adv
  • Expressly; explicitly. 

obviously

adv
  • In an obvious or clearly apparent manner. 

  • Used as a filler word, or to introduce information even when not obvious. 

  • She was in floods of tears and obviously very upset. 

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