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:
| Rank | City | Passengers | Ranking | Airline |
| --- | --- | --- | --- | --- |
| 1 | United States, Los Angeles | 14,749 |  | Alaska Airlines |
| 2 | United States, Houston | 5,465 |  | United Express |
| 3 | Canada, Calgary | 3,761 |  | Air Transat, WestJet |
| 4 | Canada, Saskatoon | 2,282 | 4 |  |
| 5 | Canada, Vancouver | 2,103 |  | Air Transat |
| 6 | United States, Phoenix | 1,829 | 1 | US Airways |
| 7 | Canada, Toronto | 1,202 | 1 | Air Transat, CanJet |
| 8 | Canada, Edmonton | 110 |  |  |
| 9 | United States, Oakland | 107 |  |  |
Question:
how many airlines have a steady ranking?
Answer:
4