user: Question: What is the earliest year where the mintage (proof) is 25,000?
Columns: ['Year', 'Theme', 'Artist', 'Mintage (Proof)', 'Issue Price (Proof)', 'Mintage (BU)[ clarification needed ]', 'Issue Price (BU)[ clarification needed ]']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [2000.0, 'Voyage of Discovery', 'D.F. Warkentin', '121,575', '$29.95', '62,975', '$19.95']
SQL:

assistant: SELECT MIN("Year") FROM "Table" WHERE "Mintage (Proof)" = '25,000';