title: How to structure data inside Core Data for the following scenario
body: <p>I have the a <code>Person</code> object store in <code>Core Data</code> which contains two attributes:</p>
  
  <ul>
  <li>name</li>
  <li>payment</li>
  </ul>
  
  <p>Now I decided I want to also store the average of payments for a day/month/year. </p>
  
  <p>How should I store this inside Core Data ? Inside the <code>Person</code> object ? Create new objects ?</p>