Table:
text: List of heirs to the Austrian throne
Heirs to the Austrian Empire
Heirs to the Austrian Empire
Emperor Heir Relationship_to_emperor_and_status Became_heir Ceased_to_be_heir Next_in_line
Franz Joseph I Crown Prince Rudolf Son Heir apparent 21 August 1858; born 30 January 1889; died Archduke Ferdinand Maximilian 1858–1864, uncle
Franz Joseph I Crown Prince Rudolf Son Heir apparent 21 August 1858; born 30 January 1889; died Archduke Karl Ludwig 1864–1889, uncle
Franz Joseph I Archduke Karl Ludwig Brother Heir presumptive 30 January 1889; nephew died 1 February 1889; renounced his succession rights Archduke Franz Ferdinand 1889, son
Franz Joseph I Archduke Karl Grandnephew Heir presumptive 28 June 1914; Death of his uncle 21 November 1916; succeeded Archduke Maximilian Eugen 1906–1912, brother
Franz Joseph I Archduke Karl Grandnephew Heir presumptive 28 June 1914; Death of his uncle 21 November 1916; succeeded Archduke Otto 1912–1916, son
Karl I Crown Prince Otto Son Heir apparent 21 November 1916; father succeeded 12 November 1918; Empire replaced by republic Archduke Robert 1916–1918, brother

Question: From the list of heirs to the Austrian throne, how many next in line did Archduke Charles have heirs?