user: Question: What is the average number of goals with 21 games for a debut round less than 1?
Columns: ['Name', 'Club', 'Debut round', 'Games (2008)', 'Goals (2008)', 'Previous club(s)']
Types: ['text', 'text', 'real', 'real', 'real', 'text']
Sample row: ['Stuart Dew Category:Articles with hCards', 'Hawthorn', 1.0, 15.0, 7.0, 'Port Adelaide (1997–2006)']
SQL:

assistant: SELECT AVG("Goals (2008)") FROM "Table" WHERE "Games (2008)" = 21.0 AND "Debut round" < 1.0;