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:
| Series # | Season # | Title | Directed by | Written by | Original air date | U.S. viewers (millions) |
| --- | --- | --- | --- | --- | --- | --- |
| 48.0 | 1.0 | " Listen to the Rain on the Roof " | Larry Shaw | Marc Cherry & Jeff Greenstein | September24,2006 | 24.09 |
| 49.0 | 2.0 | " It Takes Two " | David Grossman | Kevin Murphy & Jenna Bans | October1,2006 | 21.42 |
| 50.0 | 3.0 | " A Weekend in the Country " | Wendey Stanzler | Bob Daily | October8,2006 | 20.96 |
| 51.0 | 4.0 | " Like It Was " | Larry Shaw | John Pardee & Joey Murphy | October15,2006 | 20.64 |
| 52.0 | 5.0 | " Nice She Ain't " | David Warren | Alexandra Cunningham & Susan Nirah Jaffee | October22,2006 | 19.71 |
| 53.0 | 6.0 | " Sweetheart, I Have to Confess " | David Grossman | Dahvi Waller & Josh Senter | October29,2006 | 21.24 |
| 54.0 | 7.0 | " Bang " | Larry Shaw | Joe Keenan | November5,2006 | 22.65 |
| 55.0 | 8.0 | " Children and Art " | Wendey Stanzler | Kevin Etten & Jenna Bans | November12,2006 | 22.27 |
| 56.0 | 9.0 | " Beautiful Girls " | David Grossman | Dahvi Waller & Susan Nirah Jaffee | November19,2006 | 21.63 |
| 57.0 | 10.0 | " The Miracle Song " | Larry Shaw | Bob Daily | November26,2006 | 21.43 |
| 58.0 | 11.0 | " No Fits, No Fights, No Feuds " | Sanaa Hamri | Alexandra Cunningham & Josh Senter | January7,2007 | 18.71 |
| 59.0 | 12.0 | " Not While I'm Around " | David Grossman | Kevin Murphy & Kevin Etten | January14,2007 | 16.76 |
| 60.0 | 13.0 | " Come Play Wiz Me " | Larry Shaw | Valerie Ahern & Christian McLaughlin | January21,2007 | 17.14 |
| 61.0 | 14.0 | " I Remember That " | David Warren | John Pardee & Joey Murphy | February11,2007 | 18.10 |
| 62.0 | 15.0 | " The Little Things You Do Together " | David Grossman | Marc Cherry & Joe Keenan | February18,2007 | 18.51 |
| 63.0 | 16.0 | " My Husband, the Pig " | Larry Shaw | Brian A. Alexander | March4,2007 | 18.31 |
| 64.0 | 17.0 | " Dress Big " | Matthew Diamond | Kevin Etten & Susan Nirah Jaffee | April8,2007 | 15.93 |
| 65.0 | 18.0 | " Liaisons " | David Grossman | Jenna Bans & Alexandra Cunningham | April15,2007 | 16.35 |
| 66.0 | 19.0 | " God, That's Good " | Larry Shaw | Dahvi Waller & Josh Senter | April22,2007 | 15.91 |
| 67.0 | 20.0 | " Gossip " | Wendey Stanzler | John Pardee & Joey Murphy | April29,2007 | 17.17 |
| 68.0 | 21.0 | " Into the Woods " | David Grossman | Alexandra Cunningham | May6,2007 | 17.16 |
| 69.0 | 22.0 | " What Would We Do Without You? " | Larry Shaw | Bob Daily | May13,2007 | 16.13 |
Question:
What series number garnered 20.64 million viewers?
Answer:
51.0