Table:
Les Jackson

Personal information
Full name

Herbert Leslie Jackson

Born	(1921-04-05)5 April 1921
Whitwell, Derbyshire, England
Died	25 April 2007(2007-04-25) (aged 86)
Chesterfield, England
Batting	Right-hand bat
Bowling	Right-arm fast
Role	bowler
International information
National side

England

Test debut	23 July 1949 v New Zealand
Last Test	6 July 1961 v Australia

Domestic team information

Years	Team
1947–1963	Derbyshire

Career statistics

Competition
Tests
First-class

Matches
2
418

Runs scored
15
2083

Batting average
15.00
6.19

100s/50s
–/–
–/–

Top score
8
39*

Balls bowled
498
83267

Wickets
7
1733

Bowling average
22.14
17.36

5 wickets in innings
–
115

10 wickets in match
–
20

Best bowling
2/26
9/17

Catches/stumpings
1/–
137/–

Source: Les Jackson, 24 June 2010

This image shows a table. Tell me the row number and column number of this table. Your final answer should be in the JSON structure, formatted as {"row_number": "m", "column_number": "n"}.

There are 21 rows and 4 columns in the table. So, the final answer is {"row_number": "21", "column_number": "4"}.