user: Question: What is the lowest Year, when Surface is Hard, and when Opponent is Dinara Safina?
Columns: ['Outcome', 'Year', 'Championship', 'Surface', 'Opponent', 'Score']
Types: ['text', 'real', 'text', 'text', 'text', 'text']
Sample row: ['Winner', 1999.0, 'US Open', 'Hard', 'Martina Hingis', '6–3, 7–6 (7–4)']
SQL:

assistant: SELECT MIN("Year") FROM "Table" WHERE "Surface" = 'Hard' AND "Opponent" = 'Dinara Safina';