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:
| Outcome | Year | Championship | Surface | Partner | Opponents | Score |
| --- | --- | --- | --- | --- | --- | --- |
| Winner | 1979.0 | French Open | Clay | Bob Hewitt | Virginia Ruzici Ion Ţiriac | 6–3, 2–6, 6–3 |
| Winner | 1980.0 | US Open | Hard | Marty Riessen | Betty Stöve Frew McMillan | 7–5, 6–2 |
| Winner | 1982.0 | French Open | Clay | John Lloyd | Claudia Monteiro Cassio Motta | 6–2, 7–6 |
| Runner-up | 1982.0 | Wimbledon | Grass | John Lloyd | Anne Smith Kevin Curren | 2–6, 6–3, 7–5 |
| Winner | 1983.0 | Wimbledon | Grass | John Lloyd | Billie Jean King Steve Denton | 6–7(5), 7–6(5), 7–5 |
Question:
What was the surface for events held in 1983?
Answer:
Grass