September 30,

December 31,

2021

2020

Commercial paper program (weighted average interest rate of 0.3% as of September 30, 2021 and 0.4% as of December 31, 2020)

$

1,380

$

1,814

Senior notes, maturing through 2050, interest rates ranging from 0.75% to 7.75% (weighted average interest rate of 3.1% as of September 30, 2021 and 3.3% as of December 31, 2020)

8,126

8,465

Canadian senior notes, C$500 million maturing September 2026, interest rate of 2.6%

394

393

Tax-exempt bonds, maturing through 2048, fixed and variable interest rates ranging from 0.1% to 4.3% (weighted average interest rate of 1.5% as of September 30, 2021 and 1.7% as of December 31, 2020)

2,633

2,571

Financing leases and other, maturing through 2085, weighted average interest rate of 4.7% as of September 30, 2021 and 4.6% as of December 31, 2020 (a)

595

652

Debt issuance costs, discounts and other

(81)

(85)

13,047

13,810

Current portion of long-term debt

601

551

$

12,446

$

13,259