title: count occurrence based on 2 conditions
body: <p>Hi I have a table below where I want to count the occurrence of the credit based on Name and class.</p>
  <p>A name can have multiple class but it should count the unique credit occurrences.</p>
  <p>Any help will be highly appreciated.</p>
  <p><a href="https://i.stack.imgur.com/hEIrB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hEIrB.png" alt="enter image description here" /></a></p>