user: Question: How many episodes were seen by 0.67 million US viewers on their original air dates?
Columns: ['No. in series', 'No. in season', 'Title', 'Directed by', 'Written by', 'Original air date', 'U.S. viewers (million)']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text']
Sample row: [61.0, 1.0, '"The Unforgiven"', 'David Duchovny', 'Tom Kapinos', 'January13,2013', '1.07']
SQL:

assistant: SELECT COUNT("Original air date") FROM "Table" WHERE "U.S. viewers (million)" = '0.67';