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:
| No. in series | No. in season | Title | Directed by | Written by | Original air date | Production code | U.S. viewers (million) |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 23.0 | 1.0 | "In My Time of Dying" | Kim Manners | Eric Kripke | September28,2006 | 3T5501 | 3.93 |
| 24.0 | 2.0 | "Everybody Loves a Clown" | Phil Sgriccia | John Shiban | October5,2006 | 3T5502 | 3.34 |
| 25.0 | 3.0 | "Bloodlust" | Robert Singer | Sera Gamble | October12,2006 | 3T5503 | 3.78 |
| 26.0 | 4.0 | "Children Shouldn't Play with Dead Things" | Kim Manners | Raelle Tucker | October19,2006 | 3T5504 | 3.29 |
| 27.0 | 5.0 | "Simon Said" | Tim Lacofano | Ben Edlund | October26,2006 | 3T5505 | 3.65 |
| 28.0 | 6.0 | "No Exit" | Kim Manners | Matt Witten | November2,2006 | 3T5506 | 3.38 |
| 29.0 | 7.0 | "The Usual Suspects" | Mike Rohl | Cathryn Humphris | November9,2006 | 3T5507 | 3.19 |
| 30.0 | 8.0 | "Crossroad Blues" | Steve Boyum | Sera Gamble | November16,2006 | 3T5508 | 3.16 |
| 31.0 | 9.0 | "Croatoan" | Robert Singer | John Shiban | December7,2006 | 3T5509 | 3.12 |
| 32.0 | 10.0 | "Hunted" | Rachel Talalay | Raelle Tucker | January11,2007 | 3T5510 | 3.24 |
| 33.0 | 11.0 | "Playthings" | Charles Beeson | Matt Witten | January18,2007 | 3T5511 | 3.44 |
| 34.0 | 12.0 | "Nightshifter" | Phil Sgriccia | Ben Edlund | January25,2007 | 3T5512 | 3.42 |
| 35.0 | 13.0 | "Houses of the Holy" | Kim Manners | Sera Gamble | February1,2007 | 3T5513 | 3.37 |
| 36.0 | 14.0 | "Born Under a Bad Sign" | J. Miller Tobin | Cathryn Humphris | February8,2007 | 3T5514 | 2.84 |
| 37.0 | 15.0 | "Tall Tales" | Bradford May | John Shiban | February15,2007 | 3T5515 | 3.03 |
| 38.0 | 16.0 | "Roadkill" | Charles Beeson | Raelle Tucker | March15,2007 | 3T5516 | 3.52 |
| 39.0 | 17.0 | "Heart" | Kim Manners | Sera Gamble | March22,2007 | 3T5517 | 3.38 |
| 40.0 | 18.0 | "Hollywood Babylon" | Phil Sgriccia | Ben Edlund | April19,2007 | 3T5518 | 3.25 |
| 41.0 | 19.0 | "Folsom Prison Blues" | Mike Rohl | John Shiban | April26,2007 | 3T5519 | 3.33 |
| 42.0 | 20.0 | " What Is and What Should Never Be " | Eric Kripke | Raelle Tucker | May3,2007 | 3T5520 | 3.11 |
Question:
What's the season number of the episode viewed by 3.19 million people in the US?
Answer:
7.0