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:
| # | Air Date | Timeslot (EST) | Season | Rating | Share | 18-49 (Rating/Share) | Viewers (m) | Weekly Rank (#) |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | March 2, 2008 | Sunday 9:00 P.M. | 2007-2008 | 9.4 | 14 | 5.3/12 | 15.55 | 4 |
| 2 | March 9, 2008 | Sunday 9:00 P.M. | 2007-2008 | 7.4 | 11 | 4.1/10 | 11.83 | 10 |
| 3 | March 16, 2008 | Sunday 9:00 P.M. | 2007-2008 | 6.0 | 9 | 3.6/9 | 9.71 | 18 |
| 4 | March 23, 2008 | Sunday 9:00 P.M. | 2007-2008 | 6.1 | 10 | 3.5/9 | 9.92 | 19 |
| 5 | March 30, 2008 | Sunday 9:00 P.M. | 2007-2008 | 7.1 | 11 | 3.9/9 | 11.35 | 13 |
| 6 | April 6, 2008 | Sunday 9:00 P.M. | 2007-2008 | 5.9 | 9 | 3.2/8 | 9.42 | 27 |
| 7 | April 13, 2008 | Sunday 8:00 P.M. | 2007-2008 | 5.6 | 9 | 2.9/9 | 8.88 | 19 |
| 8 | April 20, 2008 | Sunday 8:00 P.M. | 2007-2008 | 6.4 | 10 | 3.2/9 | 10.03 | TBA |
Question:
which air date had the least viewers?
Answer:
April 13, 2008