loosely vs proportionally

loosely

adv
  • Approximately. 

  • Not tightly. 

  • Used to indicate an imprecise use of words; short for loosely speaking 

  • In a loose manner. 

proportionally

adv
  • In proportion; in due degree; adapted relatively. 

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