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 | Lane | Name | Nationality | Time | Notes |
| --- | --- | --- | --- | --- | --- |
|  | 5 | Ryan Lochte | United States | 1:53.94 | WR |
|  | 4 | Aaron Peirsol | United States | 1:54.33 |  |
|  | 8 | Arkady Vyatchanin | Russia | 1:54.93 | EU |
| 4 | 3 | Markus Rogan | Austria | 1:55.49 | NR |
| 5 | 6 | Ryosuke Irie | Japan | 1:55.72 |  |
| 6 | 1 | Hayden Stoeckel | Australia | 1:56.39 | OC |
| 7 | 2 | Răzvan Florea | Romania | 1:56.52 |  |
| 8 | 7 | Gregor Tait | Great Britain | 1:57.00 |  |
Question:
how many swimmers were from the us?
Answer:
2