How many groups of candidates are there in there in the district where the incumbent is Doc Hastings?
{'header': ['District', 'Incumbent', 'Party', 'Elected', 'Status', '2008 Candidates', 'Results'], 'page_title': 'United States House of Representatives elections in Washington, 2008', 'page_id': '', 'types': ['text', 'text', 'text', 'real', 'text', 'text', 'text'], 'id': '1-16185956-1', 'section_title': 'Races and results', 'caption': 'Races and results', 'rows': [['Washington 1', 'Jay Inslee', 'Democrat', '1998', 'Running', 'Jay Inslee (D) (cw) Larry Ishmael (R) (cw)', '68% 32%'], ['Washington 2', 'Rick Larsen', 'Democrat', '2000', 'Running', 'Rick Larsen (D) (cw) Rick Bart (R) (cw)', '62% 38%'], ['Washington 3', 'Brian Baird', 'Democrat', '1998', 'Running', 'Brian Baird (D) (cw) Michael Delavar (R) (cw)', '64% 36%'], ['Washington 4', 'Doc Hastings', 'Republican', '1994', 'Running', 'Doc Hastings (R) (cw) George Fearing (D) (cw)', '63% 37%'], ['Washington 5', 'Cathy McMorris', 'Republican', '2004', 'Running', 'Cathy McMorris (R) (cw) Mark Mays (D) (cw)', '65% 35%'], ['Washington 6', 'Norm Dicks', 'Democrat', '1976', 'Running', 'Norm Dicks (D) (cw) Doug Cloud (R) (cw)', '67% 33%'], ['Washington 7', 'Jim McDermott', 'Democrat', '1988', 'Running', 'Jim McDermott (D) (cw) Steve Beren (R) (cw)', '84% 16%'], ['Washington 8', 'Dave Reichert', 'Republican', '2004', 'Running', 'Dave Reichert (R) (cw) Darcy Burner (D) (cw)', '53% 47%']], 'name': 'table_16185956_1'}