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:
| Date | Name | Nationality | Tonnage\n(GRT) | Fate |
| --- | --- | --- | --- | --- |
| 7 October 1941 | Svend Foyn | United Kingdom | 14,795 | Damaged |
| 16 February 1942 | Monagas | Venezuela | 2,650 | Sunk |
| 16 February 1942 | San Nicholas | United Kingdom | 2,391 | Sunk |
| 16 February 1942 | Tia Juana | United Kingdom | 2,395 | Sunk |
| 22 February 1942 | J.N.Pew | United States | 9,033 | Sunk |
| 23 February 1942 | Sun | United States | 9,002 | Damaged |
| 23 February 1942 | Thalia | Panama | 8,329 | Sunk |
| 11 May 1942 | Cape of Good Hope | United Kingdom | 4,963 | Sunk |
| 24 May 1942 | Gonçalves Dias | Brazil | 4,996 | Sunk |
| 28 May 1942 | Alcoa Pilgrim | United States | 6,759 | Sunk |
| 3 June 1942 | M.F. Ellliot | United States | 6,940 | Sunk |
| 9 June 1942 | Bruxelles | Belgium | 5,085 | Sunk |
| 9 June 1942 | Franklin K. Lane | United States | 6,589 | Sunk |
| 15 June 1942 | Cold Harbor | Panama | 5,010 | Sunk |
| 15 June 1942 | Scottsburg | United States | 8,010 | Sunk |
| 15 June 1942 | West Hardaway | United States | 5,702 | Sunk |
Question:
how many ships were attacked by u-502 but not sunk?
Answer:
2