message: Document Aug 2018 ONSPD changes
diff: <tbody>
  <tr>
  <td>Release Date</td>
  - <td>May 2018</td>
  - <td>April 2018</td>
  + <td>August 2018</td>
  + <td>July 2018</td>
  </tr>
  <tr>
  <td>Data Points</td>
  - <td>1,763,093 (+0.11%)</td>
  - <td>42,206 (-4)</td>
  + <td>1,765,484 (+0.13%)</td>
  + <td>42,204 (-2)</td>
  </tr>
  </tbody>
  </table>
  