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 | Production code | U.S viewers (million) |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 118.0 | 1.0 | "My Mirror Image" (Part 2) | John Inwood | Tim Hobert | November30,2006 | 601.0 | 8.45 |
| 119.0 | 2.0 | "My Best Friend's Baby's Baby and My Baby's Baby" | Gail Mancuso | Neil Goldman & Garrett Donovan | December7,2006 | 603.0 | 8.43 |
| 120.0 | 3.0 | "My Coffee" | Rick Blue | Tad Quill | December14,2006 | 602.0 | 7.78 |
| 121.0 | 4.0 | "My House" | John Putch | Bill Callahan | January4,2007 | 604.0 | 7.33 |
| 122.0 | 5.0 | "My Friend with Money" | John Michel | Gabrielle Allan | January11,2007 | 605.0 | 7.33 |
| 123.0 | 6.0 | " My Musical " | Will Mackenzie | Debra Fordham | January18,2007 | 607.0 | 6.57 |
| 124.0 | 7.0 | "His Story IV" | Linda Mendoza | Mike Schwartz | February1,2007 | 606.0 | 6.88 |
| 125.0 | 8.0 | "My Road to Nowhere" | Mark Stegemann | Mark Stegemann | February8,2007 | 608.0 | 6.22 |
| 126.0 | 9.0 | "My Perspective" | John Putch | Angela Nissel | February15,2007 | 609.0 | 6.26 |
| 127.0 | 10.0 | "My Therapeutic Month" | Ken Whittingham | Aseem Batra | February22,2007 | 610.0 | 5.69 |
| 128.0 | 11.0 | "My Night to Remember" | Richard Davis | Debra Fordham | March1,2007 | 614.0 | 6.80 |
| 129.0 | 12.0 | "My Fishbowl" | Chris Koch | Kevin Biegel | March8,2007 | 611.0 | 5.89 |
| 130.0 | 13.0 | "My Scrubs" | John Putch | Clarence Livingston | March15,2007 | 612.0 | 6.37 |
| 131.0 | 14.0 | "My No Good Reason" (Part 1) | Zach Braff | Janae Bakken | March22,2007 | 613.0 | 6.48 |
| 132.0 | 15.0 | " My Long Goodbye " (Part 2) † | Victor Nelli, Jr. | Dave Tennant | April5,2007 | 615.0 | 4.89 |
| 133.0 | 16.0 | "My Words of Wisdom" | Victor Nelli, Jr. | Eric Weinberg | April12,2007 | 616.0 | 5.02 |
| 134.0 | 17.0 | "Their Story" | Richard Alexander Wells | Andy Schwartz | April19,2007 | 617.0 | 5.56 |
| 135.0 | 18.0 | "My Turf War" | Bill Lawrence | Sean Russell | April26,2007 | 618.0 | 4.65 |
| 136.0 | 19.0 | "My Cold Shower" | John Inwood | Janae Bakken | May3,2007 | 619.0 | 4.95 |
| 137.0 | 20.0 | "My Conventional Wisdom"† | Michael McDonald | Bill Callahan | May10,2007 | 620.0 | 5.31 |
| 138.0 | 21.0 | "My Rabbit" (Part 1) | John Putch | Kevin Biegel & Aseem Batra | May17,2007 | 621.0 | 5.21 |
Question:
What is the series number that had 5.31 million viewers?
Answer:
137.0