Table:
text: Katarina Srebotnik
Mixed doubles: 11 (5–6)
Mixed doubles: 11 (5–6)
Outcome Year_ Championship Surface Partner Opponents_in_the_final Score_in_the_final
Winner 1999 French Open Clay Piet Norval Larisa Neiland Rick Leach 6–3, 3–6, 6–3
Runner-up 2002 US Open Hard Bob Bryan Lisa Raymond Mike Bryan 6–7, 6–7
Winner 2003 US Open Hard Bob Bryan Lina Krasnoroutskaya Daniel Nestor 5–7, 7–5, 7–6 (7–5)
Runner-up 2005 US Open Hard Nenad Zimonjić Daniela Hantuchová Mahesh Bhupathi 4–6, 2–6
Winner 2006 French Open (2) Clay Nenad Zimonjić Elena Likhovtseva Daniel Nestor 6–3, 6–4
Runner-up 2007 French Open Clay Nenad Zimonjić Nathalie Dechy Andy Ram 5–7, 3–6
Runner-up 2008 French Open Clay Nenad Zimonjić Victoria Azarenka Bob Bryan 2–6, 6–7 (4–7)

Question: What surface was played on when Piet Norval was partner in mixed doubles: 11 (5–6) Katarina Srebotnik ?