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:
| Date | Tournament | Surface | Partner | Opponents in the final | Score |
| --- | --- | --- | --- | --- | --- |
| 23 July 2003 | Indianapolis, United States | Hard | Andy Ram | Diego Ayala & Robby Ginepri | 2–6, 7–6(3), 7–5 |
| 25 April 2005 | Munich , Germany | Clay | Julian Knowle | Florian Mayer & Alexander Waske | 6–3, 1–6, 6–3 |
| 11 September 2006 | Beijing, China | Hard | Mahesh Bhupathi | Michael Berrer & Kenneth Carlsen | 6–4, 6–3 |
| 26 September 2006 | Mumbai, India | Hard | Mahesh Bhupathi | Rohan Bopanna & Mustafa Ghouse | 6–4, 6–7(6), 10–8 |
| 15 June 2008 | 's-Hertogenbosch, Netherlands | Grass | Jürgen Melzer | Mahesh Bhupathi & Leander Paes | 7–6(5), 6–3 |
Question:
On which date is the tournament final with the opponents michael berrer & kenneth carlsen?
Answer:
11 September 2006