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 Speakers of the National Assembly of Guyana
Table title:
List of Speakers
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Name </th><th colspan=1 rowspan=1 > Entered office </th><th colspan=1 rowspan=1 > Left office </th></tr>
<tr> <th colspan=3 rowspan=1 > House of Assembly </th></tr>
<tr> <td colspan=1 rowspan=1 > Eustace Gordon Woolford </td><td colspan=1 rowspan=1 > 7 April 1953 </td><td colspan=1 rowspan=1 > 21 December 1953 </td></tr>
<tr> <th colspan=3 rowspan=1 > Interim Legislative Council </th></tr>
<tr> <td colspan=1 rowspan=1 > Eustace Gordon Woolford </td><td colspan=1 rowspan=1 > 5 January 1954 </td><td colspan=1 rowspan=1 > 29 June 1957 </td></tr>
<tr> <th colspan=3 rowspan=1 > Legislative Council </th></tr>
<tr> <td colspan=1 rowspan=1 > Donald Edward Jackson </td><td colspan=1 rowspan=1 > 21 August 1957 </td><td colspan=1 rowspan=1 > 18 July 1961 </td></tr>
<tr> <th colspan=3 rowspan=1 > Legislative Assembly </th></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Rahman Baccus Gajraj </td><td class="highlighted"  colspan=1 rowspan=1 > 5 October 1961 </td><td class="highlighted"  colspan=1 rowspan=1 > 25 September 1964 </td></tr>
<tr> <th colspan=3 rowspan=1 > House of Assembly </th></tr>
<tr> <td colspan=1 rowspan=1 > Aubrey Percival Alleyne </td><td colspan=1 rowspan=1 > 31 December 1964 </td><td colspan=1 rowspan=1 > 26 May 1966 </td></tr>
<tr> <th colspan=3 rowspan=1 > National Assembly </th></tr>
<tr> <td colspan=1 rowspan=1 > Aubrey Percival Alleyne </td><td colspan=1 rowspan=1 > 26 May 1966 </td><td colspan=1 rowspan=1 > 4 August 1967 </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Rahman Baccus Gajraj </td><td class="highlighted"  colspan=1 rowspan=1 > 16 February 1968 </td><td class="highlighted"  colspan=1 rowspan=1 > 4 January 1971 </td></tr>
<tr> <td colspan=1 rowspan=1 > Sase Narain </td><td colspan=1 rowspan=1 > 4 January 1971 </td><td colspan=1 rowspan=1 > 10 June 1992 </td></tr>
<tr> <td colspan=1 rowspan=1 > Derek Chunilall Jagan </td><td colspan=1 rowspan=1 > 17 December 1992 </td><td colspan=1 rowspan=1 > 15 October 2000 </td></tr>
<tr> <td colspan=1 rowspan=1 > Martin Zephyr </td><td colspan=1 rowspan=1 > 23 October 2000 </td><td colspan=1 rowspan=1 > 15 February 2001 </td></tr>
<tr> <td colspan=1 rowspan=1 > Hari Narayen Ramkaran </td><td colspan=1 rowspan=1 > 4 May 2001 </td><td colspan=1 rowspan=1 > 12 Jan 2012 </td></tr>
<tr> <td colspan=1 rowspan=1 > Raphael Trotman </td><td colspan=1 rowspan=1 > 12 Jan 2012 </td><td colspan=1 rowspan=1 > 10 Jun 2015 </td></tr>
<tr> <td colspan=1 rowspan=1 > Barton Scotland </td><td colspan=1 rowspan=1 > 10 June 2015 </td><td colspan=1 rowspan=1 >  </td></tr>
</table>
Question:
Who served as Speaker of the National Assembly of Guyana from 1961 to 1964?
Answer:
Rahman Baccus Gajraj served as Speaker of the National Assembly of Guyana from 1961 to 1964 and 1968 to 1971.