user: Question: What is larry centers' average number when there were less than 600 yards?
Columns: ['Player', 'Number', 'Yards', 'Average', 'Long', 'Touchdowns']
Types: ['text', 'real', 'real', 'real', 'real', 'real']
Sample row: ['Larry Centers', 81.0, 600.0, 7.4, 26.0, 3.0]
SQL:

assistant: SELECT AVG("Number") FROM "Table" WHERE "Player" = 'larry centers' AND "Yards" < 600.0;