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 | Athlete | Country | Time | Notes |
| --- | --- | --- | --- | --- |
|  | Yevgeny Kulikov | Soviet Union | 39.17 | OR |
|  | Valery Muratov | Soviet Union | 39.25 |  |
|  | Dan Immerfall | United States | 39.54 |  |
| 4 | Mats Wallberg | Sweden | 39.56 |  |
| 5 | Peter Mueller | United States | 39.57 |  |
| 6 | Jan Bazen | Netherlands | 39.78 |  |
| 6 | Arnulf Sunde | Norway | 39.78 |  |
| 8 | Andrey Malikov | Soviet Union | 39.85 |  |
| 9 | Oloph Granath | Sweden | 39.93 |  |
| 10 | Jim Chapin | United States | 40.09 |  |
| 11 | Tom Overend | Canada | 40.22 |  |
| 11 | Masaki Suzuki | Japan | 40.22 |  |
| 13 | Johan Granath | Sweden | 40.25 |  |
| 14 | Gaétan Boucher | Canada | 40.53 |  |
| 15 | Pertti Niittylä | Finland | 40.65 |  |
| 16 | Norio Hirate | Japan | 40.85 |  |
| 16 | Archie Marshall | Great Britain | 40.85 |  |
| 18 | Mikio Oyama | Japan | 40.90 |  |
| 19 | Hans van Helden | Netherlands | 40.91 |  |
| 19 | Emmanuel Michon | France | 40.91 |  |
| 21 | Kay Arne Stenshjemmet | Norway | 40.94 |  |
| 22 | Lee Yeong-Ha | South Korea | 41.08 |  |
| 23 | Bruno Toniolli | Italy | 41.44 |  |
| 24 | Harald Oehme | East Germany | 41.54 |  |
| 25 | Colin Coates | Australia | 41.77 |  |
| 26 | Berend Schabus | Austria | 42.33 |  |
| 27 | Heinz Steinberger | Austria | 43.28 |  |
| 28 | Jan Egil Storholt | Norway | 18.00 |  |
| - | Horst Freese | West Germany | DNF |  |
Question:
how many athletes ranked in the top 15 are from the united states?
Answer:
3