title: Power BI DAX not calculating Year over Year (YoY%) change
body: <p>I have the following DAX code:</p>
  <pre><code>VAR __PREV_YEAR =
      CALCULATE(
          SUM('data'[Inbounds]),
          DATEADD('MonthLookup'[YearMonth].[Date], -1, YEAR)
      )
  RETURN
      DIVIDE(SUM('data'[Inbounds]) - __PREV_YEAR, __PREV_YEAR)
  </code></pre>
  <p>Month Lookup Table looks like this:</p>
  <p><a href="https://i.stack.imgur.com/7atHn.png" rel="nofollow noreferrer">MonthLookup Table</a></p>
  <p>Data has a YearMonth Column as well:</p>
  <p><a href="https://i.stack.imgur.com/O3KmH.png" rel="nofollow noreferrer">YearMonth Column</a></p>
  <p>However, the DAX code shows as 0% with DateAdd based on MonthLookup, whereas setting DateAdd on data tables YearMonth results in an error.
  <a href="https://i.stack.imgur.com/aQS5T.png" rel="nofollow noreferrer">DAX YoY% change error</a></p>