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:
| Pos. | Time | Athlete | Country | Venue | Date |
| --- | --- | --- | --- | --- | --- |
| 1 | 12.21 (+0.7) | Yordanka Donkova | Bulgaria | Stara Zagora | 20 August 1988 |
| 2 | 12.25 (+1.4) | Ginka Zagorcheva | Bulgaria | Drama | 8 August 1987 |
| 3 | 12.26 (+1.7) | Ludmila Narozhilenko | Russia | Seville | 6 June 1992 |
| 3 | 12.26 (+1.2) | Brianna Rollins | United States | Des Moines | 22 June 2013 |
| 5 | 12.28 (+1.1) | Sally Pearson | Australia | Daegu | 3 September 2011 |
| 6 | 12.33 (−0.3) | Gail Devers | United States | Sacramento | 23 July 2000 |
| 7 | 12.36 (+1.9) | Grażyna Rabsztyn | Poland | Warsaw | 13 June 1980 |
| 8 | 12.37 (+1.5) | Joanna Hayes | United States | Athens | 24 August 2004 |
| 8 | 12.37 (-0.2) | Dawn Harper | United States | London | 7 August 2012 |
| 10 | 12.39 (+1.5) | Vera Komisova | Soviet Union | Rome | 5 August 1980 |
| 10 | 12.39 (+1.8) | Nataliya Grygoryeva | Soviet Union | Kiev | 11 July 1991 |
| 12 | 12.42 (+1.8) | Bettine Jahn | East Germany | Berlin | 8 June 1983 |
| 12 | 12.42 (+2.0) | Anjanette Kirkland | United States | Edmonton | 11 August 2001 |
| 14 | 12.43 (-0.9) | Lucyna Kalek | Poland | Hannover | 19 August 1984 |
| 14 | 12.43 (-0.3) | Michelle Perry | United States | Carson | 26 June 2005 |
| 14 | 12.43 (+0.2) | Lolo Jones | United States | Beijing | 18 August 2008 |
| 14 | 12.43 (+1.2) | Queen Harrison | United States | Des Moines | 22 June 2013 |
| 18 | 12.44 (-0.5) | Gloria Siebert | East Germany | Rome | 4 September 1987 |
| 18 | 12.44 (-0.8) | Olga Shishigina | Kazakhstan | Lucerne | 27 June 1995 |
| 18 | 12.44 (+0.4) | Glory Alozie | Nigeria | Monaco | 8 August 1998 |
| 18 | 12.44 (+0.6) | Damu Cherry | United States | Lausanne | 7 July 2006 |
| 22 | 12.45 (+1.3) | Cornelia Oschkenat | East Germany | Neubrandenburg | 11 June 1987 |
| 22 | 12.45 (+1.4) | Brigitte Foster-Hylton | Jamaica | Eugene | 24 May 2003 |
| 22 | 12.45 (+1.5) | Olena Krasovska | Ukraine | Athens | 24 August 2004 |
| 22 | 12.45 (+1.4) | Virginia Crawford | United States | New York City | 2 June 2007 |
Question:
how many of the athletes came from the united states?
Answer:
10