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:
SM UB-16
Table title:
Ships sunk or damaged
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Date </th><th colspan=1 rowspan=1 > Name </th><th colspan=1 rowspan=1 > Nationality </th><th colspan=1 rowspan=1 > Tonnage </th><th colspan=1 rowspan=1 > Fate </th></tr>
<tr> <td colspan=1 rowspan=1 > 3 June 1915 </td><td colspan=1 rowspan=1 > Boy Horace </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 69 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 3 June 1915 </td><td colspan=1 rowspan=1 > E&C </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 60 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 3 June 1915 </td><td colspan=1 rowspan=1 > Economy </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 56 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 12 June 1915 </td><td colspan=1 rowspan=1 > Leuctra </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 3,027 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 23 June 1915 </td><td colspan=1 rowspan=1 > Tunisiana </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 4,220 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 27 July 1915 </td><td colspan=1 rowspan=1 > Westward Ho! </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 47 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 28 July 1915 </td><td colspan=1 rowspan=1 > Mangara </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 1,821 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 8 September 1915 </td><td colspan=1 rowspan=1 > Emblem </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 50 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 8 September 1915 </td><td colspan=1 rowspan=1 > Victorious </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 43 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 10 September 1915 </td><td colspan=1 rowspan=1 > Nimrod </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 51 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 18 January 1916 </td><td colspan=1 rowspan=1 > Evelyn </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 55 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 18 January 1916 </td><td colspan=1 rowspan=1 > Foam Crest </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 46 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 19 January 1916 </td><td colspan=1 rowspan=1 > Sunshine </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 52 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 6 March 1916 </td><td colspan=1 rowspan=1 > Springflower </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 59 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 6 March 1916 </td><td colspan=1 rowspan=1 > Young Harry </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 43 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 1 April 1916 </td><td colspan=1 rowspan=1 > Perth </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 653 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 3 April 1916 </td><td colspan=1 rowspan=1 > Elziena Helena </td><td colspan=1 rowspan=1 > Netherlands </td><td colspan=1 rowspan=1 > 131 </td><td colspan=1 rowspan=1 > Damaged </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 10 April 1916 </td><td class="highlighted"  colspan=1 rowspan=1 > Robert Adamson </td><td class="highlighted"  colspan=1 rowspan=1 > United Kingdom </td><td class="highlighted"  colspan=1 rowspan=1 > 2,978 </td><td class="highlighted"  colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 22 April 1916 </td><td class="highlighted"  colspan=1 rowspan=1 > Tregantle </td><td class="highlighted"  colspan=1 rowspan=1 > United Kingdom </td><td class="highlighted"  colspan=1 rowspan=1 > 3,091 </td><td class="highlighted"  colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 2 August 1916 </td><td colspan=1 rowspan=1 > John Wilson </td><td colspan=1 rowspan=1 > Norway </td><td colspan=1 rowspan=1 > 798 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 24 August 1916 </td><td colspan=1 rowspan=1 > Velox </td><td colspan=1 rowspan=1 > Norway </td><td colspan=1 rowspan=1 > 312 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 20 April 1917 </td><td colspan=1 rowspan=1 > Arie </td><td colspan=1 rowspan=1 > Netherlands </td><td colspan=1 rowspan=1 > 107 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 26 April 1917 </td><td colspan=1 rowspan=1 > Kongsli </td><td colspan=1 rowspan=1 > Norway </td><td colspan=1 rowspan=1 > 5,822 </td><td colspan=1 rowspan=1 > Damaged </td></tr>
<tr> <td colspan=1 rowspan=1 > 9 August 1917 </td><td colspan=1 rowspan=1 > HMS Recruit </td><td colspan=1 rowspan=1 > Royal Navy </td><td colspan=1 rowspan=1 > 1,075 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 13 March 1918 </td><td colspan=1 rowspan=1 > Lisette </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 895 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 > 13 April 1918 </td><td colspan=1 rowspan=1 > Ruth </td><td colspan=1 rowspan=1 > United Kingdom </td><td colspan=1 rowspan=1 > 44 </td><td colspan=1 rowspan=1 > Sunk </td></tr>
<tr> <td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > Sunk: Damaged: Total: </td><td colspan=1 rowspan=1 > 19,652 5,953 25,605 </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 >  </td></tr>
</table>
Question:
Which British steamers did UB-16 sink in April 1916?
Answer:
UB-16 sank two British steamers: the 2,978-ton Robert Adamson on the 10thand the 3,091-ton Tregantle on the 22nd.