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:
| Congresswoman | State | Date of delivery | Mother's age | Baby gender |
| --- | --- | --- | --- | --- |
| Yvonne Braithwaite Burke | California | November 1973 | 40.0 | Girl |
| Enid Greene Waldholtz | Utah | August 1995 | 37.0 | Girl |
| Susan Molinari | New York | May 10, 1996 | 38.0 | Girl |
| Blanche Lincoln | Arkansas | June 1996 | 35.0 | Twin boys |
| Cathy McMorris Rodgers | Washington | April 29, 2007 | 37.0 | Boy |
| Kirsten Gillibrand | New York | May 15, 2008 | 41.0 | Boy |
| Stephanie Herseth Sandlin | South Dakota | December 15, 2008 | 38.0 | Boy |
| Linda Sanchez | California | May 13, 2009 | 40.0 | Boy |
| Cathy McMorris Rodgers | Washington | December 2010 | 41.0 | Girl |
| Jaime Herrera Beutler | Washington | July 15, 2013 | 34.0 | Girl |
Question:
What was the delivery date of Congresswoman Kirsten Gillibrand's baby boy?
Answer:
May 15, 2008