The Company is operated and managed geographically and has production facilities in the United States, Mexico and China. The Company utilizes reportable segment’s site contribution (site revenue minus operating expenses, excluding unrealized foreign exchange, corporate allocations and restructuring expenses) to monitor reportable segment performance. Site contribution is utilized by the chief operating decision-maker as the indicator of reportable segment performance, as it reflects costs which our operating site management is directly responsible for. Intersegment adjustments reflect intersegment sales that are generally recorded at prices that approximate arm’s-length transactions. In assessing the performance of the reportable segments, management attributes site revenue to the reportable segment that ships the product to the customer, irrespective of the product’s destination. Information about the reportable segments is as follows:

 

		Three months ended
		March 31 , 201 9				April 1 , 201 8
Revenue
Mexico		$	65,760			$	29,073
China			8,656				5,233
U.S.			29,811				5,255
Total		$	104,227			$	39,561
Intersegment revenue
Mexico		$	(34	)		$	(120	)
China			(1,427	)			(2,227	)
U.S.			(117	)			(94	)
Total		$	(1,578	)		$	(2,441	)
Net external revenue
Mexico		$	65,726			$	28,953
China			7,229				3,006
U.S.			29,694				5,161
Total segment revenue (which also equals consolidated revenue)		$	102,649			$	37,120
Site Contribution
Mexico		$	4,806			$	2,506
China			855				128
U.S.			1,423				23
Total		$	7,084			$	2,657
Corporate allocations			2,108				2,635
Restructuring charges			624				—
Unrealized foreign exchange gain on unsettled forward exchange contracts			—				(319	)
Interest			2,870				307
Income before income taxes		$	1,482			$	34

 

Three months ended March 31, 2019 (in thousands)		Mexico				U . S .				China				Total
Market Sector:
Test and Measurement		$	19,917			$	11,005			$	1,583			$	32,505
Retail and Payment Systems			12,942				—				—				12,942
Telecom, Networking and Communications			4,004				2,077				4,726				10,807
Medical			8,459				3,652				394				12,505
Industrial, Power and Clean Technology			13,099				5,979				526				19,604
Semiconductor			7,305				—				—				7,305
Aerospace and Defense			—				6,981				—				6,981
Segment Revenue			65,726				29,694				7,229				102,649

 

 

Three months ended April 1, 2018 (in thousands)		Mexico				U . S .				China				Total
Market Sector:
Test and Measurement		$	2,640			$	2,891			$	—			$	5,530
Retail and Payment Systems			7,260				—				—				7,260
Telecom, Networking and Communications			2,963				1,866				2,486				7,315
Medical			7,689				143				—				7,832
Industrial, Power and Clean Technology			2,802				262				520				3,584
Semiconductor			5,600				—				—				5,600
Aerospace and Defense			—				—				—				—
Segment Revenue			28,953				5,161				3,006				37,120

 

 

The following table contains additions, including those acquired through capital leases, to property, plant and equipment for the months ended:

 

		Three months ended
		March 3 1 , 201 9				December 30 , 201 8
Mexico		$	387			$	4,328
China			32				208
U.S.			261				1,049
Segment total			680				5,585
Corporate and other			—				118
Total		$	680			$	5,703

    

 

		March 3 1 , 201 9				December 30 , 201 8
Mexico		$	11,414			$	11,851
China			1,098				1,153
U.S			14,582				15,013
Segment total			27,094				28,017
Corporate and other			119				143
Segment assets		$	27,213			$	28,160

 

 

The following table contains geographic revenue based on the product shipment destination, for the months ended and

 

		Three months ended
		March 3 1 , 201 9				April 1 , 201 8
U.S.		$	94,186			$	30,130
Canada			5,039				5,161
China			3,424				1,829
Total		$	102,649			$	37,120

 

 

Sales of the Company’s products are concentrated in certain cases among specific customers in the same industry. The Company is subject to concentrations of credit risk in trade receivables. The Company considers concentrations of credit risk in establishing the allowance for doubtful accounts and believes the recorded allowances are adequate.

 

The Company expects to continue to depend upon a relatively small number of customers for a significant percentage of its revenue. In addition to having a limited number of customers, the Company manufactures a limited number of products for each customer. If the Company loses any of its larger customers or any product line manufactured for of its larger customers, it could experience a significant reduction in revenue. Also, the insolvency of or more of its larger customers or the inability of or more of its larger customers to pay for its orders could decrease revenue. As many costs and operating expenses are relatively fixed, a reduction in net revenue can decrease profit margins and adversely affect the business, financial condition and results of operations.

 

During the months ended customer exceeded of total revenue, comprising of of total revenue across all geographic segments. During the months ended customers exceeded of total revenue, comprising of of total revenue across all geographic segments.

 

As of customers represented more than of the trade accounts receivable. At customers comprised ( and respectively) of the Company’s trade accounts receivable. other customers individually represented more than of trade accounts receivable in either period.