annex vs include

annex

verb
  • To join; to be united. 

  • To attach or connect, as a consequence, condition, etc. 

  • To add something to another thing, especially territory; to incorporate. 

noun
  • An appendix to a book or document. 

  • An addition to the territory of a country or state, from a neighbouring country or state, normally by military force. 

  • An addition, an extension. 

  • An addition or extension to a building. 

include

verb
  • To bring into a group, class, set, or total as a (new) part or member. 

  • To use a directive that allows the use of source code from another file. 

  • To consider as part of something; to comprehend. 

noun
  • A piece of source code or other content that is dynamically retrieved for inclusion in another item. 

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