Table:
Ships sunk or damaged by SM U-28[13]

Date
Name
Tonnage
Nationality

30 June 1917
Haigh Hall
4,809
British

3 July 1917
Mongara
8,205
British

13 August 1917
Maston
3,881
British

16 August 1917
Bradford City
3,683
British

5 October 1917
Bontnewydd
3,296
British

12 January 1918
Bosforo
2,723
Italian

13 January 1918
Rapallo
3,811
British

21 January 1918
West Wales
4,336
British

8 March 1918
Mitra*
5,592
British

8 March 1918
Uganda
4,315
British

11 March 1918
Stolt Nielsen
5,684
British

Sunk:
Damaged:
Total:
44,743
5,592
50,335

Please ascertain the quantity of rows and columns within the provided table. Your final answer should be in the JSON structure, formatted as {"row_number": "m", "column_number": "n"}.

There are 13 rows and 4 columns in the table. So, the final answer is {"row_number": "13", "column_number": "4"}.