modern vs retro

modern

noun
  • Someone who lives in modern times. 

adj
  • Pertaining to the modern period (c.1800 to contemporary times), particularly in academic historiography. 

  • Pertaining to a current or recent time and style; not ancient. 

retro

noun
  • Past fashions or trends. 

adj
  • Of, or relating to, the past, past times, or the way things were. 

  • Affecting things past; retroactive, ex post facto. 

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