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. | # | Title | Directed by | Written by | U.S. viewers (million) | Original air date | Production code |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 80.0 | 1.0 | "High Exposure" | Alex Zakrzewski | Nicolas Falacci & Cheryl Heuton | 8.21 | October3,2008 | 501.0 |
| 81.0 | 2.0 | "The Decoy Effect" | Ralph Hemecker | Ken Sanzel | 8.01 | October10,2008 | 502.0 |
| 82.0 | 3.0 | "Blowback" | Dennis Smith | Robert Port | 8.68 | October17,2008 | 503.0 |
| 83.0 | 4.0 | "Jack of All Trades" | Stephen Gyllenhaal | Andrew Dettmann | 9.33 | October24,2008 | 504.0 |
| 84.0 | 5.0 | "Scan Man" | Craig Ross, Jr. | Don McGill | 10.72 | October31,2008 | 505.0 |
| 85.0 | 6.0 | "Magic Show" | John Behring | Sean Crouch | 11.28 | November7,2008 | 506.0 |
| 86.0 | 7.0 | "Charlie Don't Surf" | Emilio Estevez | Steve Hawk | 9.29 | November14,2008 | 507.0 |
| 87.0 | 8.0 | " Thirty-Six Hours " | Rod Holcomb | Julie Hébert | 11.30 | November21,2008 | 508.0 |
| 88.0 | 9.0 | "Conspiracy Theory" | Dennis Smith | Robert Port | 9.88 | December5,2008 | 509.0 |
| 89.0 | 10.0 | "Frienemies" | Steve Boyum | Nicolas Falacci & Cheryl Heuton | 9.18 | December19,2008 | 510.0 |
| 90.0 | 11.0 | " Arrow of Time " | Ken Sanzel | Ken Sanzel | 10.14 | January9,2009 | 511.0 |
| 91.0 | 12.0 | "Jacked" | Stephen Gyllenhaal | Don McGill | 11.02 | January16,2009 | 512.0 |
| 92.0 | 13.0 | "Trouble In Chinatown" | Julie Hébert | Peter MacNicol | 10.96 | January23,2009 | 513.0 |
| 93.0 | 14.0 | "Sneakerhead" | Emilio Estevez | Aaron Rahsaan Thomas | 10.30 | February6,2009 | 514.0 |
| 94.0 | 15.0 | "Guilt Trip" | Gwyneth Horder-Payton | Mary Leah Sutton | 9.10 | February13,2009 | 515.0 |
| 95.0 | 16.0 | "Cover Me" | Rob Morrow | Andrew Dettmann | 9.62 | February27,2009 | 516.0 |
| 96.0 | 17.0 | "First Law" | Steve Boyum | Sean Crouch | 10.12 | March6,2009 | 517.0 |
| 97.0 | 18.0 | "12:01 AM" | Ralph Helmecker | Robert Port | 9.51 | March13,2009 | 518.0 |
| 98.0 | 19.0 | "Animal Rites" | Ron Garcia | Julie Hébert | 9.80 | April10,2009 | 519.0 |
| 99.0 | 20.0 | " The Fifth Man " | Ken Sanzel | Don McGill | 8.82 | April24,2009 | 520.0 |
| 100.0 | 21.0 | " Disturbed " | Dennis Smith | Nicolas Falacci & Cheryl Heuton | 9.70 | May1,2009 | 521.0 |
| 101.0 | 22.0 | "Greatest Hits" | Stephen Gyllenhaal | Andrew Dettmann | 9.57 | May8,2009 | 522.0 |
Question:
What is the production code for the episode that had 9.18 million viewers (U.S.)?
Answer:
510.0