Table:
Year
Quantity in
service at
start of year
Quantity
withdrawn
Locomotive number(s)

1960
666
1
48616

1961
665
0
—

1962
665
4
48009/773–775[23]

1963
661
-3
(48773–775 reinstated)[23]

1964
664
26
etc.

1965
638
95
etc.

1966
543
162
etc.

1967
381
231
etc.

1968
150
150
48010/2/26/33/6/45/6/56/60/2/3/77/81/90
48107/11/5/7/24/32/51/3/67/8/70/82/91–3/7
48200/1/6/12/24/47/52/3/7/67/72/8/82/92/4
48304/5/7/8/17/9/21–3/5/7/9/34/5/8/40/4/5/8/51/6/65/8/9/73/4/80/4/90/2/3
48400/10/21/3/4/33/7/41/2/5/8/51/3/65/7/8/71/6/91–3
48503/4/7/10/29/32/3/44/6/9/51/3/9
48609/12/4/7/20/6/31/2/9/46/52/65/6/77/8/83/4/7/92
48700/2/15/20/2/3/7/30/40/4–6/9/50/2/63/5/73/5

For the table shown in this image, can you tell me the row and column numbers of this table? The final result should be presented in the JSON format of {"row_number": "m", "column_number": "n"}.

This table has 10 rows and 4 columns. Thus, the final answer is {"row_number": "10", "column_number": "4"}.