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 | Title | Directed by | Written by | Original air date | Production code |
| --- | --- | --- | --- | --- | --- |
| 2.0 | "Subterranean Homeboy Blues" | E.W. Swackhamer | Robert Palm | September20,1990 | 66205.0 |
| 4.0 | "Kiss the Girls and Make Them Die" | Charles Correll | Teleplay: Robert Stuart Nathan Story: Dick Wolf | October11,1990 | 66210.0 |
| 6.0 | " Everybody's Favorite Bagman " | John Patterson | Dick Wolf | October30,1990 | 83543.0 |
| 7.0 | "By Hooker, By Crook" | Martin Davidson | David Black | November13,1990 | 66203.0 |
| 9.0 | "Indifference" | James Quinn | Robert Palm | November27,1990 | 66207.0 |
| 11.0 | "Out of the Half-Light" | E. W. Swackhamer | Michael Duggan | December11,1990 | 66202.0 |
| 14.0 | "The Violence of Summer" | Don Scardino | Michael Duggan | February5,1991 | 66219.0 |
| 17.0 | "Mushrooms" | Daniel Sackheim | Robert Palm | February26,1991 | 66218.0 |
Question:
How many episodes had the production code 66210?
Answer:
1.0