How many are named River Esk
{'header': ['No.', 'Name', 'Livery', 'Arrival', 'Type', 'Configuration', 'Builder', 'Built', 'Status', 'Location'], 'page_title': 'Ravenglass and Eskdale Railway', 'section_title': 'Locomotive collection', 'caption': 'Locomotive collection', 'rows': [['3', 'River Irt', 'Mid Green', '1917', 'Steam', '0-8-2', 'Sir Arthur Heywood', '1894', 'Under overhaul', 'Workington'], ['7', 'River Esk', 'Blackberry Black', '1923', 'Steam', '2-8-2', 'Davey Paxman & Co.', '1923', 'Overhaul stalled', 'Engine shed'], ['9', 'River Mite', 'Indian Red', '1966', 'Steam', '2-8-2', 'Clarkson & Sons', '1966', 'In traffic', 'N/A'], ['10', 'Northern Rock', 'Muscat Green', '1976', 'Steam', '2-6-2', 'R&ER', '1976', 'In traffic', 'N/A'], ['BVR 1', 'Wroxham Broad', 'Sky Blue', '2013', 'Steam', '2-6-4T', 'Guest Engineering', '1964', 'In traffic', 'N/A'], ['RHDR 5', 'Hercules', 'Maroon', '2013', 'Steam', '4-8-2', 'Davey Paxman & Co.', '1927', 'In traffic', 'N/A'], ['11', 'Bonnie Dundee', 'Bronze Green', '1976', 'Steam', '0-4-2', 'Kerr Stuart', '1900', 'Stored, unserviceable', 'Carriage shed'], ['N/A', 'Synolda', 'NGR Blue', '1978', 'Steam', '4-4-2', 'Bassett-Lowke', '1912', 'Operational', 'Museum'], ['N/A', 'The Flower of the Forest', 'NER Green', '1992', 'Steam', '0-2-2', 'R&ER', '1985', 'Stored, unserviceable', 'Carriage shed'], ['6', 'Katie', 'Heywood Green', '1982', 'Steam', '0-4-0T', 'Sir Arthur Heywood', '1896', 'Stored, incomplete', 'Carriage shed'], ['ICL 1', 'Bunny', 'Green', '1922', 'Petrol-Mechanical', 'B-2', 'Francis Theakston', '1922', 'Stored, unserviceable', 'Carriage shed'], ['ICL 5', 'Quarryman', 'Fordson Green', '1927', 'Petrol-Mechanical', '4w', 'Muir-Hill', '1927', 'Stored', 'Irton Road shed'], ['ICL 4', 'Perkins', 'Yellow', '1929', 'Diesel-Mechanical', '4w-4', 'Muir-Hill', '1929', 'In traffic', 'N/A'], ['ICL 7', 'Shelagh of Eskdale', 'Apple & Brunswick Green', '1969', 'Diesel-Mechanical', '4-6-4', 'Severn-Lamb', '1969', 'Awaiting new PU', 'Headshunt'], ['ICL 8', 'Lady Wakefield', 'Brunswick Green', '1980', 'Diesel-Mechanical', 'B-B', 'R&ER', '1980', 'Under overhaul', 'TMA Engineering'], ['N/A', 'Greenbat', 'Dark Green', '1982', 'Battery-Electric', '4w', 'Greenwood & Batley', '1957', 'Stored, unserviceable', 'Headshunt'], ['ICL 9', 'Cyril', 'Unlined Green', '1985', 'Diesel-Mechanical', '4w', 'R.A. Lister', '1932', 'Station pilot', 'N/A'], ['ICL 10', 'Les', 'Dark Green', '1999', 'Diesel-Mechanical', '4w', 'R.A. Lister', '1960', 'Workshop pilot', 'N/A']]}