Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Emperor | Heir | Relationship to emperor and status | Became heir | Ceased to be heir | Next in line |
| --- | --- | --- | --- | --- | --- |
| 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 |
| Francis II | Crown Prince Ferdinand | Son Heir apparent | 11 August 1804; foundation of the Empire | 2 March 1835; succeeded | Archduke Franz Karl 1807–1835, brother |
| Ferdinand I | Archduke Franz Karl | Brother Heir presumptive | 2 March 1835; brother succeeded | 2 December 1848; renounced his succession rights | Archduke Franz ' 1835–1848, son |
| Franz Joseph I | Archduke Ferdinand Maximilian | Brother Heir presumptive | 2 December 1848; brother succeeded | 21 August 1858; son born to Emperor | Archduke Karl Ludwig 1848–1858, brother |
| 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:
How many next in lines had heirs of Archduke Karl?
Answer:
2.0