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:
List of Grand Prix motorcycle racing World Champions by year
Table title:
List
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Year </th><th colspan=1 rowspan=1 > 500cc </th><th colspan=1 rowspan=1 > 350cc </th><th colspan=1 rowspan=1 > 250cc </th><th colspan=1 rowspan=1 > 125cc </th><th colspan=1 rowspan=1 > Sidecar </th></tr>
<tr> <th colspan=1 rowspan=1 > 1949 </th><td colspan=1 rowspan=1 > United Kingdom Leslie Graham (AJS) </td><td colspan=1 rowspan=1 > United Kingdom Freddie Frith (Velocette) </td><td class="highlighted"  colspan=1 rowspan=1 > Italy Bruno Ruffo (Moto Guzzi) </td><td colspan=1 rowspan=1 > Italy Nello Pagani (Mondial) </td><td colspan=1 rowspan=1 > United Kingdom Eric Oliver United Kingdom Denis Jenkinson (Norton) </td></tr>
<tr> <th colspan=1 rowspan=1 > 1950 </th><td colspan=1 rowspan=1 > Italy Umberto Masetti (Gilera) </td><td colspan=1 rowspan=1 > United Kingdom Bob Foster (Velocette) </td><td colspan=1 rowspan=1 > Italy Dario Ambrosini (Benelli) </td><td class="highlighted"  colspan=1 rowspan=1 > Italy Bruno Ruffo (Mondial) </td><td colspan=1 rowspan=1 > United Kingdom Eric Oliver Italy Lorenzo Dobelli (Norton) </td></tr>
<tr> <th colspan=1 rowspan=1 > 1951 </th><td colspan=1 rowspan=1 > United Kingdom Geoff Duke (Norton) </td><td colspan=1 rowspan=1 > United Kingdom Geoff Duke (Norton) </td><td class="highlighted"  colspan=1 rowspan=1 > Italy Bruno Ruffo (Moto Guzzi) </td><td colspan=1 rowspan=1 > Italy Carlo Ubbiali (Mondial) </td><td colspan=1 rowspan=1 > United Kingdom Eric Oliver Italy Lorenzo Dobelli (Norton) </td></tr>
<tr> <th colspan=1 rowspan=1 > 1952 </th><td colspan=1 rowspan=1 > Italy Umberto Masetti (Gilera) </td><td colspan=1 rowspan=1 > United Kingdom Geoff Duke (Norton) </td><td colspan=1 rowspan=1 > Italy Enrico Lorenzetti (Moto Guzzi) </td><td colspan=1 rowspan=1 > United Kingdom Cecil Sandford (MV Agusta) </td><td colspan=1 rowspan=1 > United Kingdom Cyril Smith United Kingdom Bob Clements United Kingdom Les Nutt (Norton) </td></tr>
<tr> <th colspan=1 rowspan=1 > 1953 </th><td colspan=1 rowspan=1 > United Kingdom Geoff Duke (Gilera) </td><td colspan=1 rowspan=1 > United Kingdom Fergus Anderson (Moto Guzzi) </td><td colspan=1 rowspan=1 > West Germany Werner Haas (NSU) </td><td colspan=1 rowspan=1 > West Germany Werner Haas (NSU) </td><td colspan=1 rowspan=1 > United Kingdom Eric Oliver United Kingdom Stanley Dibben (Norton) </td></tr>
<tr> <th colspan=1 rowspan=1 > 1954 </th><td colspan=1 rowspan=1 > United Kingdom Geoff Duke (Gilera) </td><td colspan=1 rowspan=1 > United Kingdom Fergus Anderson (Moto Guzzi) </td><td colspan=1 rowspan=1 > West Germany Werner Haas (NSU) </td><td colspan=1 rowspan=1 > Austria Rupert Hollaus (NSU) </td><td colspan=1 rowspan=1 > West Germany Wilhelm Noll West Germany Fritz Cron (BMW) </td></tr>
<tr> <th colspan=1 rowspan=1 > 1955 </th><td colspan=1 rowspan=1 > United Kingdom Geoff Duke (Gilera) </td><td colspan=1 rowspan=1 > United Kingdom Bill Lomas (Moto Guzzi) </td><td colspan=1 rowspan=1 > West Germany Hermann Paul Müller (NSU) </td><td colspan=1 rowspan=1 > Italy Carlo Ubbiali (MV Agusta) </td><td colspan=1 rowspan=1 > West Germany Willi Faust West Germany Karl Remmert (BMW) </td></tr>
<tr> <th colspan=1 rowspan=1 > 1956 </th><td colspan=1 rowspan=1 > United Kingdom John Surtees (MV Agusta) </td><td colspan=1 rowspan=1 > United Kingdom Bill Lomas (Moto Guzzi) </td><td colspan=1 rowspan=1 > Italy Carlo Ubbiali (MV Agusta) </td><td colspan=1 rowspan=1 > Italy Carlo Ubbiali (MV Agusta) </td><td colspan=1 rowspan=1 > West Germany Wilhelm Noll West Germany Fritz Cron (BMW) </td></tr>
<tr> <th colspan=1 rowspan=1 > 1957 </th><td colspan=1 rowspan=1 > Italy Libero Liberati (Gilera) </td><td colspan=1 rowspan=1 > Australia Keith Campbell (Moto Guzzi) </td><td colspan=1 rowspan=1 > United Kingdom Cecil Sandford (Mondial) </td><td colspan=1 rowspan=1 > Italy Tarquinio Provini (Mondial) </td><td colspan=1 rowspan=1 > West Germany Fritz Hillebrand West Germany Manfred Grunwahl (BMW) </td></tr>
<tr> <th colspan=1 rowspan=1 > 1958 </th><td colspan=1 rowspan=1 > United Kingdom John Surtees (MV Agusta) </td><td colspan=1 rowspan=1 > United Kingdom John Surtees (MV Agusta) </td><td colspan=1 rowspan=1 > Italy Tarquinio Provini (MV Agusta) </td><td colspan=1 rowspan=1 > Italy Carlo Ubbiali (MV Agusta) </td><td colspan=1 rowspan=1 > West Germany Walter Schneider West Germany Hans Strauß (BMW) </td></tr>
<tr> <th colspan=1 rowspan=1 > 1959 </th><td colspan=1 rowspan=1 > United Kingdom John Surtees (MV Agusta) </td><td colspan=1 rowspan=1 > United Kingdom John Surtees (MV Agusta) </td><td colspan=1 rowspan=1 > Italy Carlo Ubbiali (MV Agusta) </td><td colspan=1 rowspan=1 > Italy Carlo Ubbiali (MV Agusta) </td><td colspan=1 rowspan=1 > West Germany Walter Schneider West Germany Hans Strauß (BMW) </td></tr>
<tr> <th colspan=1 rowspan=1 > 1960 </th><td colspan=1 rowspan=1 > United Kingdom John Surtees (MV Agusta) </td><td colspan=1 rowspan=1 > United Kingdom John Surtees (MV Agusta) </td><td colspan=1 rowspan=1 > Italy Carlo Ubbiali (MV Agusta) </td><td colspan=1 rowspan=1 > Italy Carlo Ubbiali (MV Agusta) </td><td colspan=1 rowspan=1 > West Germany Helmut Fath West Germany Alfred Wohlgemuth (BMW) </td></tr>
<tr> <th colspan=1 rowspan=1 > 1961 </th><td colspan=1 rowspan=1 > Federation of Rhodesia and Nyasaland Gary Hocking (MV Agusta) </td><td colspan=1 rowspan=1 > Federation of Rhodesia and Nyasaland Gary Hocking (MV Agusta) </td><td colspan=1 rowspan=1 > United Kingdom Mike Hailwood (Honda) </td><td colspan=1 rowspan=1 > Australia Tom Phillis (Honda) </td><td colspan=1 rowspan=1 > West Germany Max Deubel West Germany Emil Hörner (BMW) </td></tr>
</table>
Question:
How many Grand Prix World Championships has Bruno Ruffo won?
Answer:
Bruno Ruffo won three Grand Prix World Championships.