What is the pole position of the belgian grand prix?
{'header': ['Rnd', 'Race', 'Date', 'Location', 'Pole Position', 'Fastest Lap', 'Race Winner', 'Constructor', 'Report'], 'page_title': '1980 Formula One season', 'section_title': 'Championship review', 'caption': 'Championship review', 'rows': [['1', 'Argentine Grand Prix', '13 January', 'Buenos Aires', 'Alan Jones', 'Alan Jones', 'Alan Jones', 'Williams - Ford', 'Report'], ['2', 'Brazilian Grand Prix', '27 January', 'Interlagos', 'Jean-Pierre Jabouille', 'René Arnoux', 'René Arnoux', 'Renault', 'Report'], ['3', 'South African Grand Prix', '1 March', 'Kyalami', 'Jean-Pierre Jabouille', 'René Arnoux', 'René Arnoux', 'Renault', 'Report'], ['4', 'United States Grand Prix West', '30 March', 'Long Beach', 'Nelson Piquet', 'Nelson Piquet', 'Nelson Piquet', 'Brabham - Ford', 'Report'], ['5', 'Belgian Grand Prix', '4 May', 'Zolder', 'Alan Jones', 'Jacques Laffite', 'Didier Pironi', 'Ligier - Ford', 'Report'], ['6', 'Monaco Grand Prix', '18 May', 'Monaco', 'Didier Pironi', 'Carlos Reutemann', 'Carlos Reutemann', 'Williams - Ford', 'Report'], ['7', 'French Grand Prix', '29 June', 'Paul Ricard', 'Jacques Laffite', 'Alan Jones', 'Alan Jones', 'Williams - Ford', 'Report'], ['8', 'British Grand Prix', '13 July', 'Brands Hatch', 'Didier Pironi', 'Didier Pironi', 'Alan Jones', 'Williams - Ford', 'Report'], ['9', 'German Grand Prix', '10 August', 'Hockenheimring', 'Alan Jones', 'Alan Jones', 'Jacques Laffite', 'Ligier - Ford', 'Report'], ['10', 'Austrian Grand Prix', '17 August', 'Österreichring', 'René Arnoux', 'René Arnoux', 'Jean-Pierre Jabouille', 'Renault', 'Report'], ['11', 'Dutch Grand Prix', '31 August', 'Zandvoort', 'René Arnoux', 'René Arnoux', 'Nelson Piquet', 'Brabham - Ford', 'Report'], ['12', 'Italian Grand Prix', '14 September', 'Imola', 'René Arnoux', 'Alan Jones', 'Nelson Piquet', 'Brabham - Ford', 'Report'], ['13', 'Canadian Grand Prix', '28 September', 'Île Notre-Dame', 'Nelson Piquet', 'Didier Pironi', 'Alan Jones', 'Williams - Ford', 'Report']]}