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:
2004 Hungarian dual citizenship referendum
Table title:
Question I
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Choice </th><th colspan=1 rowspan=1 > Votes </th><th colspan=1 rowspan=1 > % </th></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > For </td><td colspan=1 rowspan=1 > 1,922,765 </td><td class="highlighted"  colspan=1 rowspan=1 > 65.0 </td></tr>
<tr> <td colspan=1 rowspan=1 > Against </td><td colspan=1 rowspan=1 > 1,034,578 </td><td colspan=1 rowspan=1 > 35.0 </td></tr>
<tr> <td colspan=1 rowspan=1 > Invalid/blank votes </td><td colspan=1 rowspan=1 > 53,629 </td><td colspan=1 rowspan=1 > – </td></tr>
<tr> <td colspan=1 rowspan=1 > Total </td><td colspan=1 rowspan=1 > 3,010,972 </td><td colspan=1 rowspan=1 > 100 </td></tr>
<tr> <td colspan=1 rowspan=1 > Registered voters/turnout </td><td colspan=1 rowspan=1 > 8,048,737 </td><td class="highlighted"  colspan=1 rowspan=1 > 37.5 </td></tr>
<tr> <td colspan=3 rowspan=1 > Source: Nohlen & Stöver </td></tr>
</table>
Question:
What percentage of voters turned out to vote for the referendum?
Answer:
The referendum was approved by voters, but there was a voter turnout of 37.5%