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:
| Player | No. | Nationality | Position | Years for Grizzlies | School/Club Team |
| --- | --- | --- | --- | --- | --- |
| Bobby Jackson | 24.0 | United States | Guard | 2005-2006 | Minnesota |
| Casey Jacobsen | 23.0 | United States | Guard-Forward | 2007-2008 | Stanford |
| Alexander Johnson | 32.0 | United States | Power forward | 2006-2007 | Florida State |
| Chris Johnson | 4.0 | United States | Small forward | 2013 | Dayton |
| Bobby Jones | 8.0 | United States | Forward | 2008 | Washington |
| Dahntay Jones | 30.0 | United States | Guard-Forward | 2003-2007 | Duke |
| Damon Jones | 11.0 | United States | Shooting guard | 2000-2001 | Houston |
Question:
What are the nationalities of players who attended duke?
Answer:
1.0