in january 2016 , the company issued $ 800 million of debt securities consisting of a $ 400 million aggregate principal three year fixed rate note with a coupon rate of 2.00% ( 2.00 % ) and a $ 400 million aggregate principal seven year fixed rate note with a coupon rate of 3.25% ( 3.25 % ) . the proceeds were used to repay a portion of the company 2019s outstanding commercial paper , repay the remaining term loan balance , and for general corporate purposes . the company 2019s public notes and 144a notes may be redeemed by the company at its option at redemption prices that include accrued and unpaid interest and a make-whole premium . upon the occurrence of a change of control accompanied by a downgrade of the notes below investment grade rating , within a specified time period , the company would be required to offer to repurchase the public notes and 144a notes at a price equal to 101% ( 101 % ) of the aggregate principal amount thereof , plus any accrued and unpaid interest to the date of repurchase . the public notes and 144a notes are senior unsecured and unsubordinated obligations of the company and rank equally with all other senior and unsubordinated indebtedness of the company . the company entered into a registration rights agreement in connection with the issuance of the 144a notes . subject to certain limitations set forth in the registration rights agreement , the company has agreed to ( i ) file a registration statement ( the 201cexchange offer registration statement 201d ) with respect to registered offers to exchange the 144a notes for exchange notes ( the 201cexchange notes 201d ) , which will have terms identical in all material respects to the new 10-year notes and new 30-year notes , as applicable , except that the exchange notes will not contain transfer restrictions and will not provide for any increase in the interest rate thereon in certain circumstances and ( ii ) use commercially reasonable efforts to cause the exchange offer registration statement to be declared effective within 270 days after the date of issuance of the 144a notes . until such time as the exchange offer registration statement is declared effective , the 144a notes may only be sold in accordance with rule 144a or regulation s of the securities act of 1933 , as amended . private notes the company 2019s private notes may be redeemed by the company at its option at redemption prices that include accrued and unpaid interest and a make-whole premium . upon the occurrence of specified changes of control involving the company , the company would be required to offer to repurchase the private notes at a price equal to 100% ( 100 % ) of the aggregate principal amount thereof , plus any accrued and unpaid interest to the date of repurchase . additionally , the company would be required to make a similar offer to repurchase the private notes upon the occurrence of specified merger events or asset sales involving the company , when accompanied by a downgrade of the private notes below investment grade rating , within a specified time period . the private notes are unsecured senior obligations of the company and rank equal in right of payment with all other senior indebtedness of the company . the private notes shall be unconditionally guaranteed by subsidiaries of the company in certain circumstances , as described in the note purchase agreements as amended . other debt during 2015 , the company acquired the beneficial interest in the trust owning the leased naperville facility resulting in debt assumption of $ 100.2 million and the addition of $ 135.2 million in property , plant and equipment . certain administrative , divisional , and research and development personnel are based at the naperville facility . cash paid as a result of the transaction was $ 19.8 million . the assumption of debt and the majority of the property , plant and equipment addition represented non-cash financing and investing activities , respectively . the remaining balance on the assumed debt was settled in december 2017 and was reflected in the "other" line of the table above at december 31 , 2016 . covenants and future maturities the company is in compliance with all covenants under the company 2019s outstanding indebtedness at december 31 , 2017 . as of december 31 , 2017 , the aggregate annual maturities of long-term debt for the next five years were : ( millions ) .

$ 550: 2019: 397
2020: 300
2021: 1017
2022: 497

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Questions:
as of january 2016, what was the amount equivalent to an annual interest rate of to the 3.25% ( 3.25 % ) note issued, in millions?
and what was that amount for the 2.00% ( 2.00 % ) note issued?
what was, then, in millions, the total annual interest expense combining both notes?

Answers:
13
8
21