proportion vs tranche

proportion

verb
  • To divide into proper shares; to apportion. 

  • To form symmetrically. 

  • To set or render in proportion. 

noun
  • The relation of one part to another or to the whole with respect to magnitude, quantity, or degree. 

  • Harmonious relation of parts to each other or to the whole. 

  • A quantity of something that is part of the whole amount or number. 

  • A statement of equality between two ratios. 

  • Size. 

  • Proper or equal share. 

tranche

verb
  • To divide into tranches. 

noun
  • A distinct subdivision of a single policyholder's benefits, typically relating to separate premium increments. 

  • One of a set of classes or risk maturities that compose a multiple-class security, such as a CMO or REMIC; a class of bonds. Collateralized mortgage obligations are structured with several tranches of bonds that have various maturities. 

  • A pension scheme's or scheme member's benefits relating to distinct accrual periods with different rules. 

  • A slice, section or portion. 

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