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:
The Boyz (South Korean band)
Table title:
Singles
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=2 > Title </th><th colspan=1 rowspan=2 > Year </th><th colspan=1 rowspan=1 > Peak positions </th><th colspan=1 rowspan=2 > Album </th></tr>
<tr> <th colspan=1 rowspan=1 > KOR </th></tr>
<tr> <th colspan=1 rowspan=1 > "Boy" (소년) </th><td colspan=1 rowspan=1 > 2017 </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > The First </td></tr>
<tr> <th colspan=1 rowspan=1 > "Giddy Up" </th><td class="highlighted"  colspan=1 rowspan=4 > 2018 </td><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > The Start </td></tr>
<tr> <th colspan=1 rowspan=1 > "Keeper" (지킬게) </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=2 > The Sphere </td></tr>
<tr> <th colspan=1 rowspan=1 > "Right Here" </th><td colspan=1 rowspan=1 > — </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > "No Air" </th><td colspan=1 rowspan=1 > — </td><td class="highlighted"  colspan=1 rowspan=1 > The Only </td></tr>
<tr> <th colspan=1 rowspan=1 > "Bloom Bloom" </th><td colspan=1 rowspan=1 > 2019 </td><td colspan=1 rowspan=1 > TBA </td><td colspan=1 rowspan=1 > Bloom Bloom </td></tr>
<tr> <td colspan=4 rowspan=1 > "—" denotes items that did not chart or were not released in that area. </td></tr>
</table>
Question:
What did The Boyz do in 2018?
Answer:
In 2018, The Boyz released their extended play The Only and its single "No Air".