user: Question: Which year did the Royal Canadian Mint Staff create a silver dollar?
Columns: ['Year', 'Theme', 'Artist', 'Mintage', 'Issue Price']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [2005.0, "40th Anniversary, Canada's Flag", 'William Woodruff', 'N/A', '$84.95']
SQL:

assistant: SELECT "Year" FROM "Table" WHERE "Artist" = 'Royal Canadian Mint Staff';