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:
| Location | Year | Champion | Runner-up | Score |
| --- | --- | --- | --- | --- |
| Myrtle Beach | 1976.0 | Ilie Năstase | Manuel Orantes | 6–4, 6–3 |
| Boca Raton | 1977.0 | Björn Borg | Jimmy Connors | 6–4, 5–7, 6–3 |
| Boca Raton | 1978.0 | Björn Borg | Jimmy Connors | 7–6 (7–1) , 3–6, 6–1 |
| Boca Raton | 1979.0 | Björn Borg | Jimmy Connors | 6–2, 6–3 |
| Boca Raton | 1980.0 | Björn Borg | Vitas Gerulaitis | 6–1, 5–7, 6–1 |
| Boca Raton | 1981.0 | John McEnroe | Guillermo Vilas | 6–7, 6–4, 6–0 |
Question:
What year weas John McEnroe the champion?
Answer:
1981.0