How many series are there total?
{'header': ['No. overall', 'No. in series', 'Family/families', 'Location(s)', 'Original air date'], 'page_title': '', 'page_id': '', 'types': ['text', 'real', 'text', 'text', 'text'], 'id': '1-19897294-4', 'section_title': '', 'caption': '', 'rows': [['UK4', '1', 'The Collins Family', 'Northampton', '5April2005'], ['UK5', '2', 'The Hemingway–Clegg Family', 'Yorkshire', '12April2005'], ['UK6', '3', 'The Pandit Family', 'Stevenage', '19April2005'], ['UK7', '4', 'The Douglas Family', 'Staines', '10August2005'], ['UK8', '5', 'The Cooke Family', "Bishop's Stortford", '17August2005'], ['UK9', '6', 'The Seniors Family', 'Coventry', '24August2005'], ['UK10', '7', 'The Bradbury–Lambert Family', 'Swindon', '31August2005'], ['UK11', '8', 'The Agate Family', 'Littlehampton', '7September2005'], ['UK12', '9', 'The Young Family', 'Essex', '14September2005'], ['UK13', '10', 'The Ball Family', 'South London', '21September2005'], ['UK14', '11', 'The Bixley Family', 'Peterborough', '28September2005']], 'name': 'table_19897294_4'}