limit the effects of changes in interest rates on our results of operations. As of June 30, 2020, our debt instruments consisted of borrowings under our term loans and mortgage notes.
Fixed Interest Rate Debt. As of June 30, 2020, our fixed interest rate debt consisted of $208.6 million under our mortgage notes, which included a $50.4 million variable-rate mortgage note that we effectively fixed through the use of an interest rate swap until the designated cash flow hedge expires in July 2021; and $500.0 million of borrowings under our term loans that were effectively fixed through the use of interest rate swaps. In total, our fixed interest rate debt represented 82.3% of our total consolidated debt as of June 30, 2020. Interest rate fluctuations will generally not affect our future earnings or cash flows on our fixed interest rate debt unless such instruments mature or are otherwise terminated. However, interest rate changes could affect the fair value of our fixed interest rate debt. As of June 30, 2020, the fair value and the carrying value of our fixed interest rate debt, excluding the values of hedges, was $699.7 million and $708.6 million, respectively. The fair value estimate of our fixed interest rate debt was estimated using a discounted cash flow analysis utilizing rates we would expect to pay for debt of a similar type and remaining maturity if the loans were originated on June 30, 2020. Given we generally expect to hold our fixed interest rate debt instruments to maturity or when they otherwise open up for prepayment at par, and the amounts due under such debt instruments should be limited to the outstanding principal balance and any accrued and unpaid interest at such time, we do not expect that the resulting change in fair value of our fixed interest rate debt instruments due to market fluctuations in interest rates, would have a significant impact on our operating cash flows.
Variable Interest Rate Debt. As of June 30, 2020, our consolidated variable interest rate debt consisted of $25.0 million of borrowings under our term loans and $127.0 million under our mortgage notes, which represented 17.7% of our total consolidated debt. Interest rate changes on the variable portion of our variable-rate debt could impact our future earnings and cash flows, but would not necessarily affect the fair value of such debt. As of June 30, 2020, we were exposed to market risks related to fluctuations in interest rates on $152.0 million of consolidated borrowings. A hypothetical 25 basis points increase in the all-in rate on the outstanding balance of our variable interest rate debt as of June 30, 2020, would increase our annual interest expense by approximately $0.4 million.
Derivative Instruments. As of June 30, 2020, we had 15 outstanding derivative instruments with a total notional amount of $677.4 million. These derivative instruments were comprised of interest rate swaps and interest rate caps that were designed to mitigate the risk of future interest rate increases by either providing a fixed interest rate or capping the variable interest rate for a limited, pre-determined period of time. See ���Note 4 to the Condensed Consolidated Financial Statements” for further detail on our derivative instruments. We are exposed to credit risk of the counterparty to our interest rate cap and swap agreements in the event of non-performance under the terms of the agreements. If we were not able to replace these caps or swaps in the event of non-performance by the counterparty, we would be subject to variability of the interest rate on the amount outstanding under our debt that is fixed or capped through the use of the swaps or caps, respectively.
ITEM 4. CONTROLS AND PROCEDURES
Evaluation of Disclosure Controls and Procedures
Under the direction of our principal executive officer and principal financial officer, we evaluated the effectiveness of our disclosure controls and procedures (as such term is defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”)) as of June 30, 2020. Based on this evaluation, our principal executive officer and principal financial officer have concluded that, as of June 30, 2020, our disclosure controls and procedures were effective.
Internal Control Over Financial Reporting
There have not been any changes in our internal control over financial reporting (as such term is defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) during the three months ended June 30, 2020 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.
PART II. OTHER INFORMATION
ITEM 1A. RISK FACTORS
In addition to the other information set forth in this report, you should carefully consider the risk factors discussed in Part I, Item 1A, “Risk Factors” of our 2019 Form 10-K, as supplemented by our Quarterly Reports on Form 10-Q, which could materially affect our business, financial condition, and/or future results. The risks described in our 2019 Form 10-K, as supplemented by our Quarterly Reports on Form 10-Q, are not the only risks facing us. Additional risks and uncertainties not currently known to us or that we currently deem to be immaterial also may materially adversely affect our business, financial condition, and/or operating results.