title: Group and Sum with dynamic column names
body: <p>I need to GROUP a table by Year and SUM all the possible Types (unknown) with dynamic column names.</p>
  
  <p>Sample Table:</p>
  
  <pre><code>Type|Year
  a    2001
  a    2001
  c    2002
  b    2002
  c    2003
  a    2003
  z    2003
  </code></pre>
  
  <p>Sample Result:</p>
  
  <pre><code>Year: 2001, Type_a: 2
  Year: 2002, Type_c: 1, Type_b: 1
  Year: 2003, Type_c: 1, Type_a: 1, Type_z: 1
  </code></pre>