get ahead of vs get past

get ahead of

verb
  • Used other than figuratively or idiomatically: see get, ahead, of. 

  • To take preemptive action before the development becomes reality. 

get past

verb
  • To continue around a blockage; to get around (something); to surpass something that is in the way. 

  • To cause someone to overcome a source of grief or get through a difficult time. 

  • To cause something to get around a blockage; to cause to get around or surpass something that is in the way. 

  • To get through a difficult time; to overcome a source of grief. 

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