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:
| Aces | Player | Opponent | Year | Event | Sets | Result |
| --- | --- | --- | --- | --- | --- | --- |
| 25.0 | Alexandra Stevenson | Alexandra Mueller | 2013.0 | Quebec City | 3.0 | 7–6 (9–7) , 6–7 (3–7) , 6–7 (9–11) |
| 24.0 | Serena Williams | Victoria Azarenka | 2012.0 | Wimbledon | 2.0 | 6–3, 7–6(6) |
| 24.0 | Kaia Kanepi | Lucie Safarova | 2008.0 | Tokyo | 3.0 | 4–6, 6–3, 6–4 |
| 23.0 | Serena Williams (2) | Zheng Jie | 2012.0 | Wimbledon | 3.0 | 6–7 (5–7) , 6–2, 9–7 |
| 22.0 | Alicia Molik | Venus Williams | 2007.0 | Tokyo | 2.0 | 6–7 (4–7) , 3–6 |
| 22.0 | Brenda Schultz | Iva Majoli | 1994.0 | Birmingham | 3.0 | 6–4, 5–7, 6–0 |
| 22.0 | Meghann Shaughnessy | Nicole Vaidišová | 2005.0 | Memphis | 2.0 | 7–6, 7–6 |
| 21.0 | Ekaterina Bychkova | Lindsay Lee-Waters | 2011.0 | French Open | 3.0 | 3–6, 7–6 (7–1) , 10–8 |
| 20.0 | Serena Williams (3) | Elena Dementieva | 2009.0 | Wimbledon | 3.0 | 6–7 (4–7) , 7–5, 8–6 |
| 20.0 | Serena Williams (4) | Samantha Stosur | 2012.0 | Miami | 2.0 | 7–5, 6–3 |
| 20.0 | Venus Williams | Lindsay Davenport | 1998.0 | Stanford | 3.0 | 4–6, 7–5, 4–6 |
| 20.0 | Kristina Mladenovic | Michaëlla Krajicek | 2012.0 | Brisbane | 3.0 | 7–5, 6–7 (8–10) , 6–2 |
| 20.0 | Naomi Broady | Caroline Garcia | 2011.0 | Birmingham | 3.0 | 6–2, 6–7 (5–7) , 6–4 |
| 20.0 | Nicole Vaidišová | Jelena Janković | 2006.0 | Linz | 3.0 | 5–7, 7–6 (7–5) , 6–4 |
| 20.0 | Julia Görges | Agnieszka Radwańska | 2012.0 | London (2012 Olympics) | 3.0 | 7–5, 6–7 (5–7) , 6–4 |
Question:
what's the earliest year that the wimbledon opponent was zheng jie?
Answer:
2012.0