Where was Assen held?
{'header': ['No', 'Date', 'Round', 'Circuit', 'Pole Position', 'Fastest Lap', 'Race winner', 'Report'], 'page_title': '2007 Supersport World Championship season', 'section_title': 'Season calendar', 'caption': 'Season calendar', 'rows': [['1', '24 February', 'Qatar', 'Losail', 'Kevin Curtain', 'Sébastien Charpentier', 'Kenan Sofuoğlu', 'Report'], ['2', '4 March', 'Australia', 'Phillip Island', 'Fabien Foret', 'Sébastien Charpentier', 'Fabien Foret', 'Report'], ['3', '1 April', 'Europe', 'Donington Park', 'Pere Riba', 'Katsuaki Fujiwara', 'Kenan Sofuoğlu', 'Report'], ['4', '15 April', 'Spain', 'Valencia', 'Kenan Sofuoğlu', 'Katsuaki Fujiwara', 'Kenan Sofuoğlu', 'Report'], ['5', '29 April', 'Netherlands', 'Assen', 'Kenan Sofuoğlu', 'Kenan Sofuoğlu', 'Kenan Sofuoğlu', 'Report'], ['6', '13 May', 'Italy', 'Monza', 'Kenan Sofuoğlu', 'Kenan Sofuoğlu', 'Kenan Sofuoğlu', 'Report'], ['7', '27 May', 'Great Britain', 'Silverstone', 'Sébastien Charpentier', 'Anthony West', 'Anthony West', 'Report'], ['8', '17 June', 'San Marino', 'Misano', 'Broc Parkes', 'Anthony West', 'Anthony West', 'Report'], ['9', '22 July', 'Czech Republic', 'Brno', 'Kenan Sofuoğlu', 'Kenan Sofuoğlu', 'Kenan Sofuoğlu', 'Report'], ['10', '5 August', 'Great Britain', 'Brands Hatch', 'Sébastien Charpentier', 'Broc Parkes', 'Broc Parkes', 'Report'], ['11', '9 September', 'Germany', 'EuroSpeedway Lausitz', 'Sébastien Charpentier', 'Kenan Sofuoğlu', 'Broc Parkes', 'Report'], ['12', '30 September', 'Italy', 'Vallelunga', 'Craig Jones', 'Kenan Sofuoğlu', 'Kenan Sofuoğlu', 'Report']]}