Name the number of stage winners for team columbia
{'header': ['Stage (Winner)', 'General Classification', 'Points Classification', 'Mountains Classification', 'Young Rider Classification', 'Team Classification'], 'page_title': '2008 Tour of Ireland', 'page_id': '', 'types': ['text', 'text', 'text', 'text', 'text', 'text'], 'id': '1-19115414-4', 'section_title': 'Jersey Progress', 'caption': 'Jersey Progress', 'rows': [['Stage 1 ( Mark Cavendish )', 'Mark Cavendish', 'Alexander Kristoff', 'Matt Wilson', 'Mark Cavendish', 'Topsport Vlaanderen'], ['Stage 2 ( Mark Cavendish )', 'Mark Cavendish', 'Mark Cavendish', 'Matt Wilson', 'Mark Cavendish', 'Topsport Vlaanderen'], ['Stage 3 ( Mark Cavendish )', 'Mark Cavendish', 'Mark Cavendish', 'Matt Wilson', 'Mark Cavendish', 'Topsport Vlaanderen'], ['Stage 4 ( Russell Downing )', 'Russell Downing', 'Mark Cavendish', 'Matt Wilson', 'Gonzalo Rabuñal', 'Topsport Vlaanderen'], ['Stage 5 ( František Raboň )', 'Marco Pinotti', 'Russell Downing', 'Matt Wilson', 'Simon Clarke', 'Team Columbia']], 'name': 'table_19115414_4'}