user: Question: Name the average Top 5 which has a Position of 52nd with a Year smaller than 2000?
Columns: ['Year', 'Starts', 'Wins', 'Top 5', 'Top 10', 'Poles', 'Avg. Start', 'Avg. Finish', 'Winnings', 'Position', 'Team(s)']
Types: ['real', 'real', 'real', 'real', 'real', 'real', 'real', 'real', 'text', 'text', 'text']
Sample row: [1987.0, 1.0, 0.0, 0.0, 0.0, 0.0, 35.0, 27.0, '$470', '66th', '#0']
SQL:

assistant: SELECT AVG("Top 5") FROM "Table" WHERE "Position" = '52nd' AND "Year" < 2000.0;