user: Question: What is Years, when Postition is PG, and when From is USC?
Columns: ['Player', 'Nationality', 'Jersey Number(s)', 'Position', 'Years', 'From']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Wally Walker Category:Articles with hCards', 'United States', '42', 'SF', '1977 – 1982', 'Virginia']
SQL:

assistant: SELECT "Years" FROM "Table" WHERE "Position" = 'PG' AND "From" = 'USC';