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 ambassadors of Pakistan to the United States
Table title:
List of Pakistani Ambassadors to the United States
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Name and Title </th><th colspan=1 rowspan=1 > Image </th><th colspan=1 rowspan=1 > Entered Office </th><th colspan=1 rowspan=1 > Left Office </th></tr>
<tr> <td colspan=1 rowspan=1 > Abul Hassan Isphani </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 8 October 1948 </td><td colspan=1 rowspan=1 > 8 February 1952 </td></tr>
<tr> <td colspan=1 rowspan=1 > Muhammad Ali Bogra </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 27 February 1952 </td><td colspan=1 rowspan=1 > 16 April 1953 </td></tr>
<tr> <td colspan=1 rowspan=1 > Syed Amjad Ali </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 26 September 1953 </td><td colspan=1 rowspan=1 > 17 September 1955 </td></tr>
<tr> <td colspan=1 rowspan=1 > Muhammad Ali Bogra </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > November 1955 </td><td colspan=1 rowspan=1 > March 1959 </td></tr>
<tr> <td colspan=1 rowspan=1 > Aziz Ahmed </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 23 March 1959 </td><td colspan=1 rowspan=1 > July 1963 </td></tr>
<tr> <td colspan=1 rowspan=1 > Ghulam Ahmed </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 19 July 1963 </td><td colspan=1 rowspan=1 > 15 September 1966 </td></tr>
<tr> <td colspan=1 rowspan=1 > Agha Hilaly </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 21 October 1966 </td><td colspan=1 rowspan=1 > 20 October 1971 </td></tr>
<tr> <td colspan=1 rowspan=1 > Maj Gen (R) N.A.M. Raza </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 22 October 1971 </td><td colspan=1 rowspan=1 > 22 April 1972 </td></tr>
<tr> <td colspan=1 rowspan=1 > Sultan Muhammad Khan </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 15 May 1972 </td><td colspan=1 rowspan=1 > 8 December 1973 </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Lt Gen (R) Sahabzada Yaqub Khan </td><td colspan=1 rowspan=1 >  </td><td class="highlighted"  colspan=1 rowspan=1 > 19 December 1973 </td><td colspan=1 rowspan=1 > 3 January 1979 </td></tr>
<tr> <td colspan=1 rowspan=1 > Sultan Muhammad Khan </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 13 January 1979 </td><td colspan=1 rowspan=1 > 31 December 1980 </td></tr>
<tr> <td colspan=1 rowspan=1 > Lt Gen Ejaz Azim </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 7 July 1981 </td><td colspan=1 rowspan=1 > 15 September 1986 </td></tr>
<tr> <td colspan=1 rowspan=1 > Jamsheed Marker </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 17 September 1986 </td><td colspan=1 rowspan=1 > 30 June 1989 </td></tr>
<tr> <td colspan=1 rowspan=1 > Air Chief Marshal (R) Zulfiqar Ali Khan </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 12 July 1989 </td><td colspan=1 rowspan=1 > 15 September 1990 </td></tr>
<tr> <td colspan=1 rowspan=1 > Najmuddin Shaikh </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 14 October 1990 </td><td colspan=1 rowspan=1 > 22 November 1991 </td></tr>
<tr> <td colspan=1 rowspan=1 > Abida Hussain </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 26 November 1991 </td><td colspan=1 rowspan=1 > 24 April 1993 </td></tr>
<tr> <td colspan=1 rowspan=1 > Maliha Lodhi </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 21 January 1994 </td><td colspan=1 rowspan=1 > 30 January 1997 </td></tr>
<tr> <td colspan=1 rowspan=1 > Riaz Khokhar </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 12 March 1997 </td><td colspan=1 rowspan=1 > 7 September 1999 </td></tr>
<tr> <td colspan=1 rowspan=1 > Tariq Fatemi </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 8 September 1999 </td><td colspan=1 rowspan=1 > 16 December 1999 </td></tr>
<tr> <td colspan=1 rowspan=1 > Maliha Lodhi </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 17 December 1999 </td><td colspan=1 rowspan=1 > 4 August 2002 </td></tr>
<tr> <td colspan=1 rowspan=1 > Ashraf Qazi </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 19 August 2002 </td><td colspan=1 rowspan=1 > 6 August 2004 </td></tr>
<tr> <td colspan=1 rowspan=1 > General (R) Jehangir Karamat </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 17 November 2004 </td><td colspan=1 rowspan=1 > 3 June 2006 </td></tr>
<tr> <td colspan=1 rowspan=1 > Maj Gen (R) Mahmud Ali Durrani </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 5 June 2006 </td><td colspan=1 rowspan=1 > 9 May 2008 </td></tr>
<tr> <td colspan=1 rowspan=1 > Husain Haqqani </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 26 May 2008 </td><td colspan=1 rowspan=1 > 22 November 2011 </td></tr>
<tr> <td colspan=1 rowspan=1 > Sherry Rehman </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 23 November 2011 </td><td colspan=1 rowspan=1 > 14 May 2013 </td></tr>
<tr> <td colspan=1 rowspan=1 > Jalil Abbas Jilani </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > December 2013 </td><td colspan=1 rowspan=1 > February 2017 </td></tr>
<tr> <td colspan=1 rowspan=1 > Aizaz Ahmad Chaudhry </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > March 2017 </td><td colspan=1 rowspan=1 > May 2018 </td></tr>
<tr> <td colspan=1 rowspan=1 > Ali Jehangir Siddiqui </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 29 May 2018 </td><td colspan=1 rowspan=1 > 25 December 2018 </td></tr>
<tr> <td colspan=1 rowspan=1 > Asad Majeed Khan [ja] </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 11 January 2019 </td><td colspan=1 rowspan=1 > Incumbent </td></tr>
</table>
Question:
When was Sahabzada Yaqub Khan the Pakistani Ambassador to the United States?
Answer:
Sahabzada Yaqub Khan was the Pakistani Ambassador to the United States from 19 December 1973 to 3 January 1979.