title: SQLite: Calculating Percentage of E-Mail Providers
body: <p>I've got a table filled with E-Mail addresses and was wondering how I could calculate the percentage of each E-Mail provider (e.g. G-Mail, Yahoo etc) within the table? Currently, I have:</p>
  
  <p><code>COUNT(*)/SUM(Email) AS Percentage FROM Table GROUP BY Provider</code></p>
  
  <p>But it only returns NULL values</p>