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:
| Year | Finish position | 1st day | 2nd day | 3rd day | 4th Day |
| --- | --- | --- | --- | --- | --- |
| 2008.0 | 57th | rowed-over | rowed-over | rowed-over | rowed-over |
| 2009.0 | 55th | bumped Downing | rowed-over | bumped Clare Hall | rowed-over |
| 2010.0 | 53rd | rowed-over | bumped Queens' | rowed-over | bumped Wolfson |
| 2011.0 | 46th | bumped 1st & 3rd Trinity | double over-bumped Fitzwilliam | rowed-over | bumped Robinson |
| 2012.0 | 44th | bumped Jesus | bumped King's | bumped 1st & 3rd Trinity | bumped Churchill |
Question:
How many years have a 4th Day of bumped wolfson?
Answer:
1.0