user: Question: What's the approximate number of HUs when there are more than 2 digits, and 6 levels?
Columns: ['Name', 'Level', 'Digits', 'Average size (square miles)', 'Number of HUs (approximate)', 'Example name', 'Example code (HUC)']
Types: ['text', 'real', 'real', 'text', 'real', 'text', 'real']
Sample row: ['Region', 1.0, 2.0, '177,560', 21.0, 'Pacific Northwest', 17.0]
SQL:

assistant: SELECT "Number of HUs (approximate)" FROM "Table" WHERE "Digits" > 2.0 AND "Level" = 6.0;