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:
| Round | Opponent | Date | Venue | Competition |
| --- | --- | --- | --- | --- |
| N | Whitehaven | 04/02/07 | Recreation Ground | Friendly |
| 1 | Bradford Bulls U21 | 26/02/07 | Odsal Stadium | Senior Academy Championship |
| 2 | Hull Kingston Rovers U21 | 03/03/07 | Edge Hall Road | Senior Academy Championship |
| 3 | Harlequins RL U21 | 10/03/07 | Edge Hall Road | Senior Academy Championship |
| 4 | Hull U21 | 24/03/07 | KC Stadium | Senior Academy Championship |
| 5 | St. Helens U21 | 29/03/07 | Edge Hall Road | Senior Academy Championship |
| 6 | Huddersfield Giants U21 | 14/04/07 | Galpharm Stadium | Senior Academy Championship |
| 7 | Wakefield Trinity Wildcats U21 | 22/04/07 | Edge Hall Road | Senior Academy Championship |
| 8 | Salford City Reds U21 | 27/04/07 | The Willows | Senior Academy Championship |
| N | Leigh Centurions U21 | 10/05/07 | Edge Hall Road | Friendly |
| 9 | Hull Kingston Rovers U21 | 19/05/07 | Craven Park | Senior Academy Championship |
| 10 | Hull U21 | 26/05/07 | Craven Park | Senior Academy Championship |
| 11 | Harlequins RL U21 | 02/06/07 | Twickenham Stoop | Senior Academy Championship |
| 12 | Leeds Rhinos U21 | 10/06/07 | Headingley Stadium | Senior Academy Championship |
| 13 | Wakefield Trinity Wildcats U21 | 01/07/07 | Belle Vue | Senior Academy Championship |
| 14 | Bradford Bulls U21 | 07/07/07 | Edge Hall Road | Senior Academy Championship |
| 15 | Leeds Rhinos U21 | 14/07/07 | Edge Hall Road | Senior Academy Championship |
| 16 | St Helens U21 | 20/07/07 | Knowsley Road | Senior Academy Championship |
| 17 | Warrington Wolves U21 | 04/08/07 | Halliwell Jones Stadium | Senior Academy Championship |
| 18 | Huddersfield Giants U21 | 11/08/07 | Edge Hall Road | Senior Academy Championship |
| 19 | Warrington Wolves U21 | 11/08/07 | Edge Hall Road | Senior Academy Championship |
| 20 | Salford City Reds U21 | 01/09/07 | Edge Hall Road | Senior Academy Championship |
Question:
what round saw wakefield trinity wildcats u21 as the opponenet at belle vue?
Answer:
13.0