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:
Spen Valley (UK Parliament constituency)
Table title:
Boundaries
Table:
<table id='hittask' contenteditable='False'>
<tr> <td colspan=1 rowspan=1 > Parish </td><td colspan=1 rowspan=1 > 1911 Population </td><td colspan=1 rowspan=1 > 1885-1918 </td><td colspan=1 rowspan=1 > 1918-1950 </td><td colspan=1 rowspan=1 > Notes </td></tr>
<tr> <td colspan=1 rowspan=1 > Birkenshaw </td><td colspan=1 rowspan=1 > 2,508 </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Was part of Gomersal Parish in 1885 </td></tr>
<tr> <td colspan=1 rowspan=1 > Birstall </td><td colspan=1 rowspan=1 > 7,116 </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Was part of Gomersal Parish in 1885 </td></tr>
<tr> <td colspan=1 rowspan=1 > Cleckheaton </td><td colspan=1 rowspan=1 > 12,866 </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Part of Spenborough Urban District from 1915 </td></tr>
<tr> <td colspan=1 rowspan=1 > Clifton </td><td colspan=1 rowspan=1 > 2,258 </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Elland </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Drighlington </td><td class="highlighted"  colspan=1 rowspan=1 > 4,126 </td><td class="highlighted"  colspan=1 rowspan=1 > Pudsey </td><td class="highlighted"  colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Gildersome </td><td class="highlighted"  colspan=1 rowspan=1 > 2,981 </td><td class="highlighted"  colspan=1 rowspan=1 > Pudsey </td><td class="highlighted"  colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Gomersal </td><td colspan=1 rowspan=1 > 3,796 </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Included Birkenshaw and Birstall in 1885 </td></tr>
<tr> <td colspan=1 rowspan=1 > Hartshead </td><td colspan=1 rowspan=1 > 958 </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Elland </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Heckmondwike </td><td colspan=1 rowspan=1 > 9,016 </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Hipperholme (part) </td><td colspan=1 rowspan=1 > 322 </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Elland </td><td colspan=1 rowspan=1 > Part of Wyke parish in 1885, removed in 1899 </td></tr>
<tr> <td colspan=1 rowspan=1 > Hunsworth </td><td class="highlighted"  colspan=1 rowspan=1 > 1,326 </td><td class="highlighted"  colspan=1 rowspan=1 > Pudsey </td><td class="highlighted"  colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Kirkheaton </td><td class="highlighted"  colspan=1 rowspan=1 > 2,621 </td><td class="highlighted"  colspan=1 rowspan=1 > Holmfirth </td><td class="highlighted"  colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Lepton </td><td class="highlighted"  colspan=1 rowspan=1 > 2,999 </td><td class="highlighted"  colspan=1 rowspan=1 > Holmfirth </td><td class="highlighted"  colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Liversedge </td><td colspan=1 rowspan=1 > 14,658 </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Part of Spenborough Urban District from 1915 </td></tr>
<tr> <td colspan=1 rowspan=1 > Mirfield </td><td class="highlighted"  colspan=1 rowspan=1 > 11,712 </td><td class="highlighted"  colspan=1 rowspan=1 > Morley </td><td class="highlighted"  colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Whitley Upper </td><td class="highlighted"  colspan=1 rowspan=1 > 830 </td><td class="highlighted"  colspan=1 rowspan=1 > Holmfirth </td><td class="highlighted"  colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Wyke </td><td colspan=1 rowspan=1 > 6,145 </td><td colspan=1 rowspan=1 > Spen Valley </td><td colspan=1 rowspan=1 > Bradford South </td><td colspan=1 rowspan=1 >  </td></tr>
</table>
Question:
Which Parishes joined the Spen Valley Constituency in 1918?
Answer:
The Spen Valley constituency was made up primarily of the Spen Valley, with 11,712 from Morley, 8,433 from Pudsey, and 6,450 from Holmfirth.