incur vs obtain

incur

verb
  • to bring upon oneself or expose oneself to, especially something inconvenient, harmful, or onerous; to become liable or subject to 

  • to render somebody liable or subject to 

obtain

verb
  • To get hold of; to gain possession of, to procure; to acquire, in any way. 

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