user: Question: How many next in lines had heirs of Archduke Karl?
Columns: ['Emperor', 'Heir', 'Relationship to emperor and status', 'Became heir', 'Ceased to be heir', 'Next in line']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Francis II', 'Crown Prince Ferdinand', 'Son Heir apparent', '11 August 1804; foundation of the Empire', '2 March 1835; succeeded', 'Archduke Joseph Franz 1804–1807, brother']
SQL:

assistant: SELECT COUNT("Next in line") FROM "Table" WHERE "Heir" = 'Archduke Karl';