Table:
Year Ended December 31,	Year Ended December 31,	Year Ended December 31,

2019	2018	2017

(As percentage of net revenues)	(As percentage of net revenues)	(As percentage of net revenues)

OEM	70%	65%	66%

Distribution	30	35	34

Total	100%	100%	100%

I need you to conduct the following task:
Given this table image, find all merged table cells and return merged regions with the JSON {'top-left':(A, B), 'bottom-right':(C, D)},  where (A, B) and (C, D) indicate the (row_id, column_id) of top-left and bottom-right cells in the merged regions, respectively. You should remember that row id and column id start from 1.

This table does not contain any merged cells.