	As of June 30, 2019			As of December 31, 2018
Revolving credit facility(A)	$	40,627		$	28,059
Term loan		200,000			200,000
Australian term loan facility(B)		842,400			—
4.000% Senior Unsecured Notes due 2022(C)		568,650			573,350
5.500% Senior Unsecured Notes due 2024		300,000			300,000
6.375% Senior Unsecured Notes due 2024		500,000			500,000
3.325% Senior Unsecured Notes due 2025(C)		568,650			573,350
5.250% Senior Unsecured Notes due 2026		500,000			500,000
5.000% Senior Unsecured Notes due 2027		1,400,000			1,400,000
	$	4,920,327		$	4,074,759
Debt issue costs, net		(42,017	)		(37,370	)
	$	4,878,310		$	4,037,389

As of June 30, 2019, principal payments due on our debt (which exclude the effects of any discounts, premiums, or debt issue costs recorded) are as follows (in thousands):

2019	$	—
2020		—
2021		40,627
2022		768,650
2023		—
Thereafter		4,111,050
Total	$	4,920,327

On May 23, 2019, we entered into an AUD$1.2 billion term loan facility agreement with Bank of America, N.A., as administrative agent, and several lenders from time to time are parties thereto. The term loan facility matures on May 23, 2024. We used the proceeds under the facility to finance our acquisition of the Healthscope portfolio. The interest rate under the term loan is adjustable based on a pricing grid from 0.85% to 1.65%, dependent on our current senior unsecured credit rating. On June 27, 2019, we entered into an interest rate swap transaction (effective July 3, 2019) to fix the interest rate to approximately 1.20% for the duration of the loan. The current applicable margin for the pricing grid (which can vary based on the Company’s credit rating) is 1.25% for an all-in fixed rate of 2.45%. We paid approximately $8 million in one-time structuring and underwriting fees associated with this term loan facility.

Our debt facilities impose certain restrictions on us, including restrictions on our ability to: incur debts; create or incur liens; provide guarantees in respect of obligations of any other entity; make redemptions and repurchases of our capital stock; prepay, redeem or repurchase debt; engage in mergers or consolidations; enter into affiliated transactions; dispose of real estate or other assets; and change our business. In addition, the credit agreements governing our revolving credit and term loan agreement (“Credit Facility”) limit the amount of dividends we can pay as a percentage of normalized adjusted funds from operations, as defined in the agreements, on a rolling four quarter basis. At June 30, 2019, the dividend restriction was 95% of normalized adjusted funds from operations (“NAFFO”). The indentures governing our senior unsecured notes also limit the amount of dividends we can pay based on the sum of 95% of NAFFO, proceeds of equity issuances and certain other net cash proceeds. Finally, our senior unsecured notes require us to maintain total unencumbered assets (as defined in the related indenture) of not less than 150% of our unsecured indebtedness.

In addition to these restrictions, the Credit Facility contains customary financial and operating covenants, including covenants relating to our total leverage ratio, fixed charge coverage ratio, secured leverage ratio, consolidated adjusted net worth, unsecured leverage ratio, and unsecured interest coverage ratio. This Credit Facility also contains customary events of default, including among

others, nonpayment of principal or interest, material inaccuracy of representations and failure to comply with our covenants. If an event of default occurs and is continuing under the Credit Facility, the entire outstanding balance may become immediately due and payable. At June 30, 2019, we were in compliance with all such financial and operating covenants.