(1)	Weighted average effective interest rate as of June 30, 2020.

(2)	Includes variable rate mortgages payable with interest rate cap agreements.

(3)	Includes variable rate mortgages payable with interest rates fixed by interest rate swap agreements.

As of June 30, 2020 and December 31, 2019, the net carrying value of real estate collateralizing our mortgages payable totaled $1.6 billion and $1.4 billion. Our mortgages payable contain covenants that limit our ability to incur additional indebtedness on these properties and, in certain circumstances, require lender approval of tenant leases and/or yield maintenance upon repayment prior to maturity. Certain of our mortgages payable are recourse to us. See Note 17 for additional information.

During the six months ended June 30, 2020, we entered into a mortgage loan with a principal balance of $175.0 million collateralized by 4747 Bethesda Avenue, and refinanced the mortgage loan collateralized by RTC-West, increasing the principal balance by $20.2 million. In July 2020, we entered into three separate mortgage loans with an aggregate principal balance of $385.0 million, collateralized by The Bartlett, 1221 Van Street and 220 20th Street.

As of June 30, 2020 and December 31, 2019, we had various interest rate swap and cap agreements on certain of our mortgages payable with an aggregate notional value of $945.4 million and $867.6 million. See Note 15 for additional information.

Credit Facility

As of June 30, 2020, our $1.4 billion credit facility consisted of a $1.0 billion revolving credit facility maturing in January 2025, a $200.0 million unsecured term loan ("Tranche A-1 Term Loan") maturing in January 2023, and a $200.0 million unsecured term loan ("Tranche A-2 Term Loan") maturing in July 2024. The following is a summary of amounts outstanding under the credit facility:


	Effective
	Interest Rate ⁽¹⁾	June 30, 2020		December 31, 2019

		(In thousands)
Revolving credit facility ^{(2) (3) (4)}	1.21%	$	500,000	$	200,000

Tranche A-1 Term Loan ⁽⁵⁾	2.34%	$	200,000	$	100,000
Tranche A-2 Term Loan ⁽⁶⁾	2.49%		200,000		200,000
Unsecured term loans			400,000		300,000
Unamortized deferred financing costs, net			(2,363)		(2,705)
Unsecured term loans, net		$	397,637	$	297,295

(1)	Effective interest rate as of June 30, 2020.

(2)	As of both June 30, 2020 and December 31, 2019, letters of credit with an aggregate face amount of $1.5 million were outstanding under our revolving credit facility.

(3)	As of June 30, 2020 and December 31, 2019, net deferred financing costs related to our revolving credit facility totaling $7.5 million and $3.1 million were included in "Other assets, net."

(4)	The interest rate for our revolving credit facility excludes a 0.15% facility fee. In July 2020, we repaid the $500.0 million outstanding on our revolving credit facility.

(5)

As of both June 30, 2020 and December 31, 2019, $100.0 million of the outstanding balance was fixed by interest rate swap agreements. As of June 30, 2020, the interest rate swaps mature concurrently with the term loan and provide a weighted average interest rate of 1.14%. As of June 30, 2020, we had a forward-starting swap that became effective on July 20, 2020 with a notional value of $100.0 million, which effectively converted the variable interest rate applicable to the remaining $100.0 million drawn in April 2020 under our Tranche A-1 Loan to a fixed interest rate upon the effective date of the swap.

(6)	As of June 30, 2020 and December 31, 2019, $200.0 million and $137.6 million of the outstanding balance was fixed by interest rate swap agreements. As of June 30, 2020, the interest rate swaps mature concurrently with the term loan and provide a weighted average interest rate of 1.34%.