Table:
text: Martina Navratilova career statistics
Doubles: 37 (31–6)
Doubles: 37 (31–6)
Outcome Year_ Championship Surface Partner Opponents Score
Winner 1975 French Open Clay Chris Evert Julie Anthony Olga Morozova 6–3, 6–2
Winner 1976 Wimbledon Grass Chris Evert Billie Jean King Betty Stöve 6–1, 3–6, 7–5
Runner-up 1977 Wimbledon Grass Betty Stöve Helen Gourlay JoAnne Russell 6–3, 6–3
Winner 1977 US Open Clay Betty Stöve Renee Richards Betty Ann Grubb Stuart 6–1, 7–6
Winner 1978 US Open (2) Hard Billie Jean King Kerry Reid Wendy Turnbull 7–6, 6–4
Winner 1979 Wimbledon (2) Grass Billie Jean King Betty Stöve Wendy Turnbull 5–7, 6–3, 6–2
Runner-up 1979 US Open Hard Billie Jean King Betty Stöve Wendy Turnbull 7–5, 6–3

text: Martina Navratilova career statistics
Doubles: 37 (31–6)
Doubles: 37 (31–6)
Outcome Year_ Championship Surface Partner Opponents Score
Runner-up 1985 US Open Hard Pam Shriver Claudia Kohde-Kilsch Helena Suková 6–7, 6–2, 6–3
Winner 1985 Australian Open (5) Grass Pam Shriver Claudia Kohde-Kilsch Helena Suková 6–3, 6–4
Winner 1986 French Open (5) Clay Andrea Temesvári Steffi Graf Gabriela Sabatini 6–1, 6–2
Winner 1986 Wimbledon (7) Grass Pam Shriver Hana Mandlíková Wendy Turnbull 6–1, 6–3
Winner 1986 US Open (6) Hard Pam Shriver Hana Mandlíková Wendy Turnbull 6–4, 3–6, 6–3
Winner 1987 Australian Open (6) Grass Pam Shriver Zina Garrison Lori McNeil 6–1, 6–0
Winner 1987 French Open (6) Clay Pam Shriver Steffi Graf Gabriela Sabatini 6–2, 6–1
Winner 1987 US Open (7) Hard Pam Shriver Kathy Jordan Elizabeth Smylie 5–7, 6–4, 6–2

Question: What is the surface of Doubles 37 31 6 Martina Navratilova career stats if US Open is the championship in 1979?