high tech vs knotty

high tech

noun
  • high technology; the most advanced technology available. 

  • A Late Modern architectural style incorporating elements of high-technology industry and seeking to communicate the underlying structure and function of a building. 

knotty

adj
  • Of a part of the body, a tree, etc.: full of knots (knobs or swellings); gnarled, knobbly. 

  • Of string or something stringlike: full of, or tied up, in knots. 

  • Complicated or tricky; complex, difficult. 

  • Of an austere or hard nature; rugged. 

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