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 Norfolk Legislative Assembly
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> <td colspan=1 rowspan=1 > Hon. David Ernest Buffett </td><td colspan=1 rowspan=1 > ? </td><td colspan=1 rowspan=1 > ? </td></tr>
<tr> <td colspan=1 rowspan=1 > Hon. John Terence Brown </td><td colspan=1 rowspan=1 > 21 May 1986 </td><td colspan=1 rowspan=1 > 22 May 1989 </td></tr>
<tr> <td colspan=1 rowspan=1 > Hon. David Ernest Buffett </td><td colspan=1 rowspan=1 > 22 May 1989 </td><td colspan=1 rowspan=1 > 20 May 1992 </td></tr>
<tr> <td colspan=1 rowspan=1 > Hon. John Terence Brown </td><td colspan=1 rowspan=1 > 20 May 1992 </td><td colspan=1 rowspan=1 > 4 May 1994 </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Hon. David Ernest Buffett </td><td class="highlighted"  colspan=1 rowspan=1 > 4 May 1994 </td><td class="highlighted"  colspan=1 rowspan=1 > 1997 </td></tr>
<tr> <td colspan=1 rowspan=1 > Hon. George Charles Smith </td><td colspan=1 rowspan=1 > 5 May 1997 </td><td colspan=1 rowspan=1 > 2000 </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Hon. David Ernest Buffett </td><td class="highlighted"  colspan=1 rowspan=1 > 28 February 2000 </td><td class="highlighted"  colspan=1 rowspan=1 > 2006 </td></tr>
<tr> <td colspan=1 rowspan=1 > Hon. Geoffrey Robert Gardner </td><td colspan=1 rowspan=1 > 1 February 2006 </td><td colspan=1 rowspan=1 > 27 March 2007 </td></tr>
<tr> <td colspan=1 rowspan=1 > Hon. Lisle Denis Snell </td><td colspan=1 rowspan=1 > 28 March 2007 </td><td colspan=1 rowspan=1 > 24 March 2010 </td></tr>
<tr> <td colspan=1 rowspan=1 > Hon. Robin-Eleanor Adams </td><td colspan=1 rowspan=1 > 24 March 2010 </td><td colspan=1 rowspan=1 > 20 March 2013 </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Hon. David Ernest Buffett </td><td class="highlighted"  colspan=1 rowspan=1 > 20 March 2013 </td><td colspan=1 rowspan=1 > 17 June 2015 </td></tr>
</table>
Question:
When was David Ernest Buffett speaker of the Assembly?
Answer:
Buffet was elected as Speaker of the Norfolk Legislative Assembly on 20 March 2013 and had previously served as Speaker from 1994–1997 and 2000–2006.