| 1 | A | B | C | D | E | F | G | H | I |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 2 | managerial statistics |  |  |  |  |  |  |  |  |
| 3 | team | from | to | record |  |  |  |  |  |
| 4 |  |  |  | g | w | d | l | win % | ref |
| 5 | fc wil | 1 july 1988 | 30 june 1993 | - |  |  |  |  |  |
| 6 | grasshoppers | 1 july 1993 | 19 november 1997 | 161 | 88 | 41 | 32 | 54.66 | none |
| 7 | tottenham hotspur | 20 november 1997 | 6 september 1998 | 30 | 10 | 8 | 12 | 33.33 | none |
| 8 | basel | 1 july 1999 | 27 may 2009 | 498 | 289 | 115 | 94 | 58.03 | none |
| 9 | vfb stuttgart | 6 december 2009 | 13 october 2010 | 36 | 20 | 7 | 9 | 55.56 | none |
| 10 | young boys | 8 may 2011 | 30 april 2012 | 40 | 16 | 15 | 9 | 40.00 | none |
| 11 | al-ahli | 1 july 2014 | 1 july 2016 | 82 | 57 | 19 | 6 | 69.51 | none |
| 12 | al-ahli | 2 october 2016 | 20 june 2017 | 37 | 24 | 6 | 7 | 64.86 | none |
| 13 | zamalek sc | 13 july 2018 | present | 45 | 26 | 13 | 6 | 57.78 | none |
| 14 | total |  |  | 904 | 512 | 219 | 173 | 56.64 | - |

Question: when did christian gross become the manager of basel?
Answer: 1 july 1999