RE vs per

RE

prep
  • Regarding, re. 

noun
  • Abbreviation of "recursively enumerable"; the class of decision problems for which a 'yes' answer can be verified by a Turing machine in a finite amount of time. 

per

prep
  • In accordance with, as per 

  • For each. 

  • By the, by means of the, via the, through the. 

  • To each, in each (used in expressing ratios of units). 

pron
  • They (singular). Gender-neutral neologistic third-person singular subject pronoun, coordinate with gendered pronouns he and she. 

  • Them (singular) Neologistic gender-neutral third-person singular object pronoun, suggested for use in place of him and her. 

adj
  • Belonging to per, their (singular). Gender-neutral third-person singular possessive adjective, coordinate with gendered his and her. 

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