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:
2006 Tokelauan self-determination referendum
Table title:
Results
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 colspan=1 rowspan=1 > Referendum failed Against </td><td colspan=1 rowspan=1 > 232 </td><td colspan=1 rowspan=1 > 39.93 </td></tr>
<tr> <td colspan=1 rowspan=1 > For </td><td colspan=1 rowspan=1 > 349 </td><td colspan=1 rowspan=1 > 60.07 </td></tr>
<tr> <td colspan=1 rowspan=1 > Required majority </td><td colspan=2 rowspan=1 > 66.67 </td></tr>
<tr> <td colspan=1 rowspan=1 > Valid votes </td><td class="highlighted"  colspan=1 rowspan=1 > 581 </td><td colspan=1 rowspan=1 > 99.49 </td></tr>
<tr> <td colspan=1 rowspan=1 > Invalid or blank votes </td><td class="highlighted"  colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > 0.51 </td></tr>
<tr> <td colspan=1 rowspan=1 > Total votes </td><td colspan=1 rowspan=1 > 584 </td><td colspan=1 rowspan=1 > 100.00 </td></tr>
<tr> <td colspan=1 rowspan=1 > Registered voters and turnout </td><td class="highlighted"  colspan=1 rowspan=1 > 615 </td><td colspan=1 rowspan=1 > 94.96 </td></tr>
</table>
Question:
How many valid votes were cast, how many invalid votes were cast, and what was the overall voter turnout?
Answer:
581 of the 615 eligible voters cast a proper ballot (3 ruined ballots were also cast).