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

2019	2018	2017	2019 vs 2018	2018 vs 2017

(In millions)	(In millions)	(In millions)

Cost of sales	$(5,860)	$(5,803)	$(5,075)	1.0%	(14.3)%

Gross profit	$3,696	$3,861	$3,272	(4.3)%	18.0%

Gross margin (as percentage of net revenues)	38.7%	40.0%	39.2%	-130 bps	+80 bps

Different merged cells often exist in a table and they can be represented by the JSON {'top-left':(x, y), 'bottom-right':(m, n)}. In this JSON item, '(x, y)' and '(m, n)' 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.

This table does not contain any merged cells.