10. Debt

1.375% Convertible Senior Notes

On March 6, 2017, the Company completed a private offering of $400 million principal amount convertible senior notes (the "Notes"). The Notes bear interest semi-annually at a rate of 1.375% per year and will mature on March 1, 2022, unless repurchased, redeemed or converted at an earlier date. The Company used $72.5 million of the proceeds to pay off the then remaining balance under its credit agreement.

The Notes are convertible at an initial conversion rate of 10.7744 shares of common stock per $1,000 principal amount of the Notes, or approximately 4.3 million shares of common stock, which is equivalent to a conversion price of approximately $92.81 per share. The conversion rate is subject to adjustment under certain circumstances. Holders may convert the Notes under the following circumstances: during any calendar quarter after the calendar quarter ended on June 30, 2017 if the closing price of the Company's common stock for at least 20 trading days in the 30 consecutive trading days ending on the last trading day of the preceding calendar quarter is greater than or equal to 130% of the conversion price of the Notes; during the five business day period after any ten consecutive trading day period (the "measurement period") in which the trading price per $1,000 principal amount of notes for each trading day of the measurement period was less than 98% of the product of the closing sale price of our common stock and the conversion rate on each such trading day; if specified distributions or corporate events occur; if the Notes are called for redemption; or at any time after December 1, 2021. The Company may redeem all or any portion of the Notes, at its option, on or after March 6, 2020, if the last reported sale price of the Company's common stock has been at least 130% of the conversion price then in effect for at least 20 trading days during any 30 consecutive trading day period. Upon conversion, the Notes may be settled in cash, shares of the Company's common stock or a combination of cash and shares, at the Company's election.

The principal balance of the Notes was separated into liability and equity components, and was recorded initially at fair value. The excess of the principal amount of the liability component over its carrying amount represents the debt discount, which is amortized to interest expense over the term of the Notes using the effective interest method. The carrying amount of the liability component was estimated by discounting the contractual cash flows of similar non-convertible debt at an appropriate market rate at the date of issuance.

The Company incurred debt issuance costs of approximately $10.6 million, which was allocated to the liability and equity components in proportion to the allocation of the proceeds. The costs allocated to the liability component are being amortized as interest expense over the term of the Notes using the effective interest method.

The carrying amount of the Notes consisted of the following (in thousands):

	December 29, 2018			December 30, 2017

Liability component
Principal	$	400,000		$	400,000
Unamortized debt discount		(39,298	)		(50,499	)
Unamortized debt issuance costs		(5,931	)		(7,622	)

Net carrying amount	$	354,771		$	341,879



Equity component
Net carrying amount	$	57,735		$	57,735

The liability component of the Notes is recorded in convertible debt on the Consolidated Balance Sheet. The equity component of the Notes is recorded in additional paid-in capital. The effective interest rate for the liability component was 4.75%. As of December 29, 2018, the remaining period over which the debt discount and debt issuance costs will be amortized was 3.2 years.

Interest expense related to the Notes was comprised of the following (in thousands):

	Year Ended

	December 29, 2018		December 30, 2017
Contractual interest expense	$	5,500	$	4,492
Amortization of debt discount		11,202		8,816
Amortization of debt issuance costs		1,690		1,330

	$	18,392	$	14,638

Credit Facility

In connection with the Company's offering of the Notes, it and certain of its domestic subsidiaries (the "Guarantors") amended its existing credit agreement and paid off the then remaining balance of $72.5 million. The amended agreement (the "Credit Facility") consists of a $300 million revolving credit facility with a maturity date of July 24, 2020. The Credit Facility includes a $25 million letter of credit sublimit and a $10 million swingline loan sublimit. The Company also has an option to increase the size of the borrowing capacity by up to an aggregate of $200 million in additional commitments, subject to certain conditions.

The revolving credit facility, other than swingline loans, will bear interest at the Eurodollar rate plus an applicable margin or, at the option of the Company, a base rate (defined as the highest of the Wells Fargo prime rate, the Federal Funds rate plus 0.50% and the Eurodollar Base Rate plus 1.00%) plus an applicable margin. Swingline loans accrue interest at the base rate plus the applicable margin for base rate loans. The applicable margins for the Eurodollar rate loans range from 1.25% to 2.00% and for base rate loans range from 0.25% to 1.00%, depending in each case, on the leverage ratio as defined in the Credit Facility.

The Credit Facility contains various conditions, covenants and representations with which the Company must be in compliance in order to borrow funds and to avoid an event of default, including financial covenants that the Company must maintain a leverage ratio (funded debt/EBITDA) of no more than 3.00 to 1 and a minimum fixed charge coverage ratio (EBITDA/interest payments, income taxes and capital expenditures) of no less than 1.25 to 1. As of December 29, 2018, the Company was in compliance with all covenants of the Credit Facility. The Company's obligations under the Credit Facility are guaranteed by the Guarantors and are secured by a security interest in substantially all assets of the Company and the Guarantors.