td><td> 8</td>
        </tr>
        <tr>
          <td>18</td><td> 19</td><td> 9</td>
        </tr>
        <tr>
          <td>19</td><td> 22</td><td> 9</td>
        </tr>
        <tr>
          <td>20</td><td> 27</td><td>11</td>
        </tr>
        <tr>
          <td>21</td><td> 28</td><td>11</td>
        </tr>
      </table>
    </p>

    <h3 align = "center">
      Licensing:
    </h3>

    <p>
      The computer code and data files described and made available on this
      web page are distributed u