Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| By-election | Electorate | Date | Incumbent | Reason | Winner |
| --- | --- | --- | --- | --- | --- |
| 1882.0 | Franklin North | 9 June | Benjamin Harris | Election declared void | Benjamin Harris |
| 1882.0 | Wakanui | 16 June | Cathcart Wason | Election declared void | Joseph Ivess |
| 1882.0 | Stanmore | 11 July | Walter Pilliet | Election declared void | Walter Pilliet |
| 1883.0 | Peninsula | 22 January | James Seaton | Death | William Larnach |
| 1883.0 | Selwyn | 6 April | John Hall | Resignation | Edward James Lee |
| 1883.0 | Inangahua | 14 May | Thomas Shailer Weston | Resignation | Edward Shaw |
| 1883.0 | Bruce | 29 June | James Rutherford | Death | James McDonald |
| 1884.0 | Selwyn | 15 February | Edward James Lee | Death | Edward Wakefield |
| 1884.0 | Thorndon | 13 May | William Levin | Resignation | Alfred Newman |
| 1884.0 | Kaiapoi | 16 May | Isaac Wilson | Resignation | Edward Richardson |
Question:
When james rutherford is the incumbent how many dates are there?
Answer:
1.0