user: Question: How much Average has a Team of san lorenzo, and a 1990-1991 smaller than 45?
Columns: ['Team', 'Average', 'Points', 'Played', '1988-89', '1989-90', '1990-1991']
Types: ['text', 'real', 'real', 'real', 'text', 'text', 'real']
Sample row: ['Boca Juniors', 1.254, 143.0, 114.0, '49', '43', 51.0]
SQL:

assistant: SELECT "Average" FROM "Table" WHERE "Team" = 'san lorenzo' AND "1990-1991" < 45.0;