user: Question: How many Years have a % 'B' Aggregates of 28%, and an Average A's per learner smaller than 3.2800000000000002?
Columns: ['Year', 'Pass Rate', "% 'A' Aggregates", "% 'B' Aggregates", "% 'A' or 'B' Aggregates", "Average A's per learner"]
Types: ['real', 'text', 'text', 'text', 'text', 'real']
Sample row: [2007.0, '100%', '56%', '28%', '84%', 3.28]
SQL:

assistant: SELECT COUNT("Year") FROM "Table" WHERE "% 'B' Aggregates" = '28%' AND "Average A's per learner" < 3.2800000000000002;