Interest Expense and Loss on Debt Extinguishment and Repurchase. Our interest expense resulted from interest incurred on our $329.1 million of senior secured notes due 2022 (“2022 Notes”), interest incurred on our $189.2 million of senior unsecured notes due 2021 (“2021 Notes") until these notes were repurchased in June 2020, interest incurred on our installment payment agreement, interest incurred on our finance lease obligations and interest incurred on our €350.0 million aggregate principal amount of senior unsecured notes due 2024 (“2024 Notes”). We issued €215.0 million of our 2024 Notes in June 2020 and €135.0 million of our 2024 Notes were issued in June 2019. In June 2020, we redeemed and extinguished our 2021 Notes at par value. In March 2021, we repurchased and extinguished $115.9 million of our 2022 Notes at 103.24% of par value resulting in a loss on debt extinguishment and repurchase of $3.9 million and reduced the par value from $445.0 million to $329.1 million. Our interest expense increased by 4.0% for the three months ended March 31, 2021 from the three months ended March 31, 2020 primarily due to an increase in our finance lease obligations and the issuances of our 2024 Notes, partly offset by the June 2020 repurchase of our 2021 Notes and the March 2021 partial extinguishment of our 2022 Notes.
Unrealized Gain on Foreign Exchange on 2024 Notes. Our 2024 Notes were issued in Euros and are reported in our reporting currency – US Dollars. As of March 31, 2021, the carrying value of our €350.0 million 2024 Notes was $410.5 million. Our unrealized gain on foreign exchange on our 2024 Notes from converting our 2024 Notes into US Dollars was an unrealized gain of $18.9 million for the three months ended March 31, 2021 and an unrealized gain of $2.9 million for the three months ended March 31, 2020. We have not entered into hedges for our foreign currency obligations.
Income Tax Provision. Our income tax provision was $7.4 million for the three months ended March 31, 2021 and $3.6 million for the three months ended March 31, 2020. The increase in our income tax expense is primarily related to an increase in our income before income taxes.
Buildings On-net. As of March 31, 2021 and 2020, we had a total of 2,939 and 2,823 on-net buildings connected to our network, respectively. The increase in our on-net buildings was a result of our disciplined network expansion program. We anticipate adding a similar number of buildings to our network for the next several years.
Liquidity and Capital Resources
In assessing our liquidity, management reviews and analyzes our current cash balances, accounts receivable, accounts payable, accrued liabilities, capital expenditure commitments, and required finance lease and debt payments and other obligations.
Over the next several years we have significant contractual and anticipated cash outlays including our indicative dividend payments on our common stock, our maturing debt obligations, interest payments on our debt obligations and our projected capital expenditure requirements in order to help execute our business plan. Based upon our historical growth rate of our dividend, we expect that we would have to provide approximately $320 million in order to meet our expected quarterly dividend payments over the next two years. In March 2021, we redeemed and extinguished $115.9 million of our 2022 Notes. On April 6, 2021 we issued a notice of conditional partial redemption for $45.0 million of our 2022 Notes. The remaining $284.1 million of our original $445.0 million 2022 Notes mature in March 2022 and include annual interest payments of $15.3 million if held until maturity.
Our €350 million of 2024 Notes mature in June 2024 and include annual interest payments €15.3 million until maturity. Our 2024 Notes are denominated in Euros and expose us to potentially unfavorable adverse movements in foreign currency rate changes. Our overseas operations provides us access to Euros, however these amounts may be insufficient to fund our obligations under our 2024 Notes. Additionally, we have not entered into forward exchange contracts related to our foreign currency exposure.
We may need to or elect to refinance all or a portion of our indebtedness at or before maturity and we cannot provide assurances that we will be able to refinance any such indebtedness on commercially reasonable terms or at all. In addition, we may elect to secure additional capital in the future, at acceptable terms, to improve our liquidity or fund acquisitions or for general corporate purposes. In addition, in an effort to reduce future cash interest payments as well as future amounts due at maturity or to extend debt maturities, we may, from time to time, issue new debt, enter into debt for debt, or cash transactions to purchase our outstanding debt securities in the open market or through privately negotiated transactions. We will evaluate any such transactions in light of the existing market conditions. The amounts involved in any such transaction, individually or in the aggregate, may be material.