Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
British Best All-Rounder
Table title:
Winners
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Year </th><th colspan=1 rowspan=1 > Winner (men) </th><th colspan=1 rowspan=1 > Club </th><th colspan=1 rowspan=1 > Average speed (mph) </th></tr>
<tr> <td colspan=1 rowspan=1 > 1947 </td><td colspan=1 rowspan=1 > Albert Derbyshire </td><td colspan=1 rowspan=1 > Calleva RC </td><td colspan=1 rowspan=1 > 22.744 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1946 </td><td colspan=1 rowspan=1 > Albert Derbyshire </td><td colspan=1 rowspan=1 > Calleva RC </td><td colspan=1 rowspan=1 > 22.843 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1945 </td><td colspan=1 rowspan=1 > Jock Allison </td><td colspan=1 rowspan=1 > Musselburgh RC </td><td colspan=1 rowspan=1 > 22.479 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1944 </td><td colspan=1 rowspan=1 > Albert Derbyshire </td><td colspan=1 rowspan=1 > Calleva RC </td><td colspan=1 rowspan=1 > 23.549 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1939 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1938 </td><td colspan=1 rowspan=1 > H. 'Shake' Earnshaw </td><td colspan=1 rowspan=1 > Monkton CC </td><td colspan=1 rowspan=1 > 22.627 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1937 </td><td colspan=1 rowspan=1 > Cyril Heppleston </td><td colspan=1 rowspan=1 > Yorkshire RC </td><td colspan=1 rowspan=1 > 22.348 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1936 </td><td colspan=1 rowspan=1 > Charles Holland </td><td colspan=1 rowspan=1 > Midland C&AC </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1935 </td><td colspan=1 rowspan=1 > Stanley W. Miles </td><td colspan=1 rowspan=1 > Century RC </td><td colspan=1 rowspan=1 > 21.809 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1934 </td><td colspan=1 rowspan=1 > Ernest J. Capell </td><td colspan=1 rowspan=1 > Allondon RC </td><td colspan=1 rowspan=1 > 21.622 </td></tr>
<tr> <td colspan=1 rowspan=1 > 1933 </td><td class="highlighted"  colspan=1 rowspan=1 > Frank Southall </td><td colspan=1 rowspan=1 > Norwood Paragon CC </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1932 </td><td class="highlighted"  colspan=1 rowspan=1 > Frank Southall </td><td colspan=1 rowspan=1 > Norwood Paragon CC </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1931 </td><td class="highlighted"  colspan=1 rowspan=1 > Frank Southall </td><td colspan=1 rowspan=1 > Norwood Paragon CC </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 1930 </td><td class="highlighted"  colspan=1 rowspan=1 > Frank Southall </td><td colspan=1 rowspan=1 > Norwood Paragon CC </td><td class="highlighted"  colspan=1 rowspan=1 > 21.141 </td></tr>
</table>
Question:
How successful was Frank Southall?
Answer:
Frank Southall averaged 21.141 mph and won again the following three years.