97 CP 2020 ANNUAL REPORT Changes in Accumulated other comprehensive loss by component are as follows: Amounts in Pension and post-retirement defined benefit plans reclassified from Accumulated other comprehensive loss are as follows: 9. Accounts receivable, net For the twelve months ended December 31, 2020 (in millions of Canadian dollars) Freight Non-Freight Total Allowance for credit losses, opening balance $ (27) $ (16) $ (43) Current period credit loss provision, net 2  1  3  Allowance for credit losses, closing balance $ (25) $ (15) $ (40) (1) As at December 31, 2020 As at December 31, 2019 (in millions of Canadian dollars) Freight Non-Freight Total Freight Non-Freight Total Total accounts receivable $ 662 $ 203 $ 865 $ 637  $ 210  $ 847  Allowance for credit losses (25) (15) (40) (26) (16) (42) Total accounts receivable, net $ 637 $ 188 $ 825 $ 611  $ 194  $ 805  (1) (in millions of Canadian dollars) 2020 2019 Amortization of prior service costs $ (1) $ —  Recognition of net actuarial loss 180 84  Total before income tax 179 84  Income tax recovery (47) (20) Total net of income tax $ 132 $ 64  (1) (1) (in millions of Canadian dollars) Foreign currency net of hedging activities Derivatives and other Pension and post- retirement defined benefit plans Total Opening balance, January 1, 2020 $ 112 $ (54) $ (2,580) $ (2,522) Other comprehensive loss before reclassifications — (2) (430) (432) Amounts reclassified from accumulated other comprehensive loss — 8 132 140 Net other comprehensive income (loss) — 6 (298) (292) Closing balance, December 31, 2020 $ 112 $ (48) $ (2,878) $ (2,814) Opening balance, January 1, 2019 $ 113  $ (62) $ (2,094) $ (2,043) Other comprehensive loss before reclassifications (1) —  (550) (551) Amounts reclassified from accumulated other comprehensive loss —  8  64  72  Net other comprehensive (loss) income (1) 8  (486) (479) Closing balance, December 31, 2019 $ 112  $ (54) $ (2,580) $ (2,522) (1) (1) (1) (1) Amounts are presented net of tax. (1)  Impacts "Other components of net periodic benefit recovery" on the Consolidated Statements of Income. (1)   Prior year amounts have not been adjusted under the modified retrospective method (Note 2). (1)  Opening balance at January 1, 2020 was restated as described in Note 2. (1)