user: Question: Which Annual ridership (2008) has a Number of stations larger than 70, and an Annual ridership (1998) smaller than 451971849?
Columns: ['Line', 'Operator', 'Line length (kilometres)', 'Number of stations', 'Annual ridership (1998)', 'Annual ridership (2008)']
Types: ['text', 'text', 'real', 'real', 'real', 'real']
Sample row: ['Mitre', 'UGOMS', 1855.0, 55.0, 84081493.0, 73207048.0]
SQL:

assistant: SELECT "Annual ridership (2008)" FROM "Table" WHERE "Number of stations" > 70.0 AND "Annual ridership (1998)" < 451971849.0;