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:
| Name | Canton | District | Area\n(km²) | Population\n(As of 2005) | Date of law |
| --- | --- | --- | --- | --- | --- |
| Diekirch\nDikrech | Diekirch | Diekirch | 12.42 | 6,165 | 24 February 1843 |
| Differdange\nDéifferdeng | Esch-sur-Alzette | Luxembourg | 22.18 | 19,005 | 4 August 1907 |
| Dudelange\nDiddeleng | Esch-sur-Alzette | Luxembourg | 21.38 | 17,618 | 4 August 1907 |
| Echternach\nIechternach | Echternach | Grevenmacher | 20.49 | 4,507 | 24 February 1843 |
| Esch-sur-Alzette\nEsch-Uelzecht | Esch-sur-Alzette | Luxembourg | 14.35 | 28,000 | 29 May 1906 |
| Ettelbruck\nEttelbréck | Diekirch | Diekirch | 15.18 | 7,364 | 4 August 1907 |
| Grevenmacher\nGréiwemaacher | Grevenmacher | Grevenmacher | 16.48 | 3,966 | 24 February 1843 |
| Luxembourg City\nLëtzebuerg | Luxembourg | Luxembourg | 51.46 | 76,420 | 24 February 1843 |
| Remich\nRéimech | Remich | Grevenmacher | 5.29 | 2,986 | 24 February 1843 |
| Rumelange\nRëmeleng | Esch-sur-Alzette | Luxembourg | 6.83 | 4,495 | 4 August 1907 |
| Vianden\nVeianen | Vianden | Diekirch | 9.67 | 1,561 | 24 February 1843 |
| Wiltz\nWolz | Wiltz | Diekirch | 19.37 | 4,587 | 24 February 1843 |
Question:
how many luxembourg cities had a date of law of feb 24, 1843?
Answer:
7