Table:
factor
%
95% confidence interval

from
to

discomfort or injury involving a laser product

yes
1.1
0.7
1.4

no
98.9
98.5
99.2

discomfort or injury involving laser product-number of times

1 time
44.9
27.6
62.1

2 to 260 times
49.5
32.2
66.7

type of discomfort or injury

skin
41.3
24.1
58.5

eye
59.1
41.9
76.3

length of discomfort or injury

two days or less
63.9
45.2
82.6

more than two days
34.0
15.2
52.9

own use or someone else's

your own use of the device
25.0
12.1
37.8

someone else's use of the device
74.9
62.0
87.7

type of laser that caused injury, excluding medical devices

pointer
26.3
11.7
40.9

cosmetic treatments
39.1
21.7
56.6

survey tool / entertainment / materials processing / scanner / other
34.1
18.4
49.8

Could you analyze the table shown in the image and inform me about all the merged cell regions? Use the JSON {'top-left':(X, Y), 'bottom-right':(Z, W)} to represent each merged area, with (X, Y) as the (first row, first column) and (Z, W) as the (last row, last column). Note that the X, Y, Z, W all start from 1.

The merged cell regions are as follows:
{'top-left':(1, 1), 'bottom-right':(2, 1)}
{'top-left':(1, 2), 'bottom-right':(2, 2)}
{'top-left':(1, 3), 'bottom-right':(1, 4)}
{'top-left':(3, 2), 'bottom-right':(3, 4)}
{'top-left':(6, 2), 'bottom-right':(6, 4)}
{'top-left':(9, 2), 'bottom-right':(9, 4)}
{'top-left':(12, 2), 'bottom-right':(12, 4)}
{'top-left':(15, 2), 'bottom-right':(15, 4)}
{'top-left':(18, 2), 'bottom-right':(18, 4)}.