How many different second members were there when John rudhale was first member?
{'header': ['Elected', 'Assembled', 'Dissolved', 'First member', 'Second member'], 'page_title': '', 'page_id': '', 'types': ['real', 'text', 'text', 'text', 'text'], 'id': '1-15451122-2', 'section_title': '', 'caption': '', 'rows': [['1604', '19 March 1604', '9 February 1611', 'Sir James Scudamore', 'Sir Herbert Croft'], ['1614', '5 April 1614', '7 June 1614', 'Sir James Scudamore', 'Sir Herbert Croft'], ['1621', '16 January 1621', '8 February 1622', 'Sir John Scudamore, Bt', 'Fitzwilliam Coningsby'], ['1624', '12 February 1624', '27 March 1625', 'Sir John Scudamore, Bt', 'Sir Robert Harley'], ['1625', '17 May 1625', '12 August 1625', 'John Rudhale', 'Sir Giles Brydges, Bt'], ['1626', '6 February 1626', '15 June 1626', 'Sir Robert Harley', 'Sir Walter Pye'], ['1628', '17 March 1628', '10 March 1629', 'Sir Giles Brydges, Bt', 'Sir Walter Pye']], 'name': 'table_15451122_2'}