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:
| Code | County | Former Province | Area (km 2 ) | Population Census 2009 | Capital |
| --- | --- | --- | --- | --- | --- |
| 18.0 | Nyandarua | Central | 3,107.7 | 596268.0 | Ol Kalou |
| 19.0 | Nyeri | Central | 2,361.0 | 693558.0 | Nyeri |
| 20.0 | Kirinyaga | Central | 1,205.4 | 528054.0 | Kerugoya / Kutus |
| 21.0 | Murang'a | Central | 2,325.8 | 942581.0 | Murang'a |
| 22.0 | Kiambu | Central | 2,449.2 | 1623282.0 | Kiambu |
Question:
What capital has a population of 596268?
Answer:
Ol Kalou