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:
Tove Styrke
Table title:
Singles
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=2 > Year </th><th colspan=1 rowspan=2 > Single </th><th colspan=3 rowspan=1 > Peak chart positions </th><th colspan=1 rowspan=2 > Certifications </th><th colspan=1 rowspan=2 > Album </th></tr>
<tr> <th colspan=1 rowspan=1 > SWE </th><th colspan=1 rowspan=1 > BEL (FL) </th><th colspan=1 rowspan=1 > GER </th></tr>
<tr> <td colspan=1 rowspan=2 > 2010 </td><th colspan=1 rowspan=1 > "Million Pieces" </th><td colspan=1 rowspan=1 > 18 </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=5 > Tove Styrke </td></tr>
<tr> <th colspan=1 rowspan=1 > "White Light Moment" </th><td colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > SWE: Gold </td></tr>
<tr> <td colspan=1 rowspan=2 > 2011 </td><th colspan=1 rowspan=1 > "High and Low" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=1 rowspan=1 > "Call My Name" </th><td colspan=1 rowspan=1 > 28 </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > 48 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 2012 </td><th colspan=1 rowspan=1 > "Bad Time for a Good Time" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=2 > 2014 </td><th colspan=1 rowspan=1 > "Even If I'm Loud It Doesn't Mean I'm Talking to You" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td><td class="highlighted"  colspan=1 rowspan=4 > Kiddo </td></tr>
<tr> <th colspan=1 rowspan=1 > "Borderline" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > SWE: Gold </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=3 > 2015 </td><th class="highlighted"  colspan=1 rowspan=1 > "Ego" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=1 rowspan=1 > "Number One" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=1 rowspan=1 > "...Baby One More Time" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > Non-album single </td></tr>
<tr> <td colspan=1 rowspan=3 > 2017 </td><th colspan=1 rowspan=1 > "Say My Name" </th><td colspan=1 rowspan=1 > 85 </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=7 > Sway </td></tr>
<tr> <th colspan=1 rowspan=1 > "Mistakes" </th><td colspan=1 rowspan=1 > 42 </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=1 rowspan=1 > "Liability (demo)" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=4 > 2018 </td><th colspan=1 rowspan=1 > "Changed My Mind" </th><td colspan=1 rowspan=1 > 90 </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=1 rowspan=1 > "On the Low" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=1 rowspan=1 > "Sway" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=1 rowspan=1 > "Vibe" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > 2019 </td><th colspan=1 rowspan=1 > "Love Me Back" (with Ritual) </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > Non-album single </td></tr>
</table>
Question:
What did Tove Styrke do in 2015?
Answer:
In 2015, Tove Styrke premiered the single "Ego" from her second album, Kiddo.