user: Question: What was the best top five result when the average start is 28.5? 
Columns: ['Year', 'Starts', 'Wins', 'Top 5', 'Top 10', 'Poles', 'Avg. Start', 'Avg. Finish', 'Winnings', 'Position', 'Team(s)']
Types: ['real', 'real', 'real', 'real', 'real', 'real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1989.0, 1.0, 0.0, 0.0, 0.0, 0.0, '15.0', '30.0', '$500', '98th', '#16 Day Enterprise Racing']
SQL:

assistant: SELECT MAX("Top 5") FROM "Table" WHERE "Avg. Start" = '28.5';