user: Question: What is the average Episode Number, when Original Airdate is march 21, 2010, and when Season is less than 3?
Columns: ['Year', 'Show', 'Season', 'Episode', 'Episode number', 'Original airdate']
Types: ['real', 'text', 'real', 'text', 'real', 'text']
Sample row: [1995.0, 'The X-Files', 2.0, '" Soft Light "', 23.0, 'May 5, 1995']
SQL:

assistant: SELECT AVG("Episode number") FROM "Table" WHERE "Original airdate" = 'march 21, 2010' AND "Season" < 3.0;