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 (km2) | Population\nCensus 2009 | Capital |
| --- | --- | --- | --- | --- | --- |
| 1 | Mombasa | Coast | 212.5 | 939,370 | Mombasa (City) |
| 2 | Kwale | Coast | 8,270.3 | 649,931 | Kwale |
| 3 | Kilifi | Coast | 12,245.9 | 1,109,735 | Kilifi |
| 4 | Tana River | Coast | 35,375.8 | 240,075 | Hola |
| 5 | Lamu | Coast | 6,497.7 | 101,539 | Lamu |
| 6 | Taita-Taveta | Coast | 17,083.9 | 284,657 | Voi |
|  | Totals |  | 79,686.1 | 3,325,307 | - |
Question:
how many counties have a population greater than 500,000?
Answer:
3