Table:
highest certificate, diploma or degree
female lone parents
female parent in couples

1991
2001
2011
difference
1991
2001
2011
difference

percent

total
100
100
100
..
100
100
100
..

no certificate, diploma or degree
34
20
13
-21
24
13
8
-16

high school diploma or equivalency
30
28
25
-5
32
28
21
-11

postsecondary certificate below the bachelor's level
26
39
42
16
29
36
38
9

university degree at the bachelor's level or above
9
13
20
11
15
23
33
18

Different merged cells often exist in a table and they can be represented by the JSON {'top-left':(R1, C1), 'bottom-right':(R2, C2)}. In this JSON item, '(R1, C1)' and '(R2, C2)' are the (row_id, column_id) coordinates for the top-left and bottom-right cells in the merged region, respectively. Please examine the provided table image, identify all merged cells, and return their details using the above-mentioned format. Remember, the numbering for both rows and columns starts at 1.

The merged cell regions are as follows:
{'top-left':(1, 1), 'bottom-right':(3, 1)}
{'top-left':(1, 2), 'bottom-right':(1, 5)}
{'top-left':(1, 6), 'bottom-right':(1, 9)}
{'top-left':(3, 2), 'bottom-right':(3, 9)}.