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 season | No. disc | Title | Directed by | Written by | Original air date |
| --- | --- | --- | --- | --- | --- |
| 1.0 | 1.0 | "The Serpent's Lair (4)" | Jonathan Glassner | Brad Wright | June26,1998 ( Showtime ) |
| 2.0 | 1.0 | "In the Line of Duty" | Martin Wood | Robert C. Cooper | July3,1998 (Showtime) |
| 3.0 | 1.0 | "Prisoners" | David Warry-Smith | Terry Curtis Fox | July10,1998 (Showtime) |
| 6.0 | 2.0 | "Thor's Chariot" | William Gereghty | Katharyn Powers | July31,1998 (Showtime) |
| 8.0 | 2.0 | "Family" | William Gereghty | Katharyn Powers | August14,1998 (Showtime) |
| 9.0 | 2.0 | "Secrets" | Duane Clark | Terry Curtis Fox | August21,1998 (Showtime) |
| 10.0 | 3.0 | "Bane" | David Warry-Smith | Robert C. Cooper | September25,1998 (Showtime) |
| 11.0 | 3.0 | "The Tok'ra (Part 1)" | Brad Turner | Jonathan Glassner | October2,1998 (Showtime) |
| 12.0 | 3.0 | "The Tok'ra (Part 2)" | Brad Turner | Jonathan Glassner | October9,1998 (Showtime) |
| 13.0 | 3.0 | "Spirits" | Martin Wood | Tor Alexander Valenza | October23,1998 (Showtime) |
| 14.0 | 3.0 | "Touchstone" | Brad Turner | Sam Egan | October30,1998 (Showtime) |
| 15.0 | 4.0 | "A Matter of Time" | Jimmy Kaufman | Story: Misha Rashovichm Teleplay: Brad Wright | January29,1999 (Sky One) |
| 17.0 | 4.0 | "Serpent's Song" | Peter DeLuise | Katharyn Powers | February12,1999 (Sky One) |
| 19.0 | 5.0 | "One False Step" | William Corcoran | Michael Kaplan & John Sanborn | February19,1999 (Sky One) |
| 20.0 | 5.0 | "Show and Tell" | Peter DeLuise | Jonathan Glassner | February26,1999 (Sky One) |
| 21.0 | 5.0 | "1969" | Charles Correll | Brad Wright | March5,1999 (Sky One) |
Question:
How many original air dates were there for episode 17?
Answer:
1.0