bestead vs subserve

bestead

verb
  • To help, assist. 

  • To profit; benefit; serve; avail. 

  • To take the place of; replace. 

subserve

verb
  • To assist in carrying out. 

  • To serve to promote (an end); to be useful to. 

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