Concentration of Credit Risk

6 Months Ended

Jan. 28, 2017

The Company’s customer base is highly concentrated, with its top five customers during each of the six months ended January 28, 2017 and January 23, 2016 accounting for approximately 75.5% and 66.7% of its total contract revenues, respectively. Customers whose contract revenues exceeded 10% of total contract revenue during the three or six months ended January 28, 2017 or January 23, 2016 were as follows:



	For the Three Months Ended		For the Six Months Ended
	January 28, 2017	January 23, 2016	January 28, 2017	January 23, 2016
AT&T Inc.	28.3%	22.4%	28.7%	20.6%
Comcast Corporation	16.7%	13.5%	15.8%	12.7%
CenturyLink, Inc.	16.5%	14.9%	16.1%	15.3%
Verizon Communications Inc.	8.8%	11.9%	9.1%	10.7%

Customers whose combined amounts of trade accounts receivable and costs and estimated earnings in excess of billings, net (“CIEB, net”) exceeded 10% of total combined trade receivables and CIEB, net as of January 28, 2017 or July 30, 2016 were as follows (dollars in millions):



	January 28, 2017			July 30, 2016
	Amount		% of Total	Amount		% of Total
Comcast Corporation	$	126.4	18.5%	$	95.3	13.9%
AT&T Inc.	$	118.9	17.4%	$	138.8	20.3%
Windstream Corporation	$	97.6	14.3%	$	79.0	11.5%
CenturyLink, Inc.	$	79.7	11.7%	$	79.0	11.5%
Verizon Communications Inc.	$	63.2	9.3%	$	69.0	10.1%

In addition, another customer had combined amounts of trade accounts receivable and CIEB, net of $75.6 million, or 11.1%, as of January 28, 2017, and $71.5 million, or 10.4%, as of July 30, 2016.

The Company believes that none of its significant customers were experiencing financial difficulties that would materially impact the collectability of the Company’s trade accounts receivable and costs in excess of billings as of January 28, 2017. See Note 4, Accounts Receivable, and Note 5, Costs and Estimated Earnings in Excess of Billings, for additional information regarding the Company’s trade accounts receivable and costs and estimated earnings in excess of billings.