Note 11. INVENTORIES 101 Total inventories include fair value adjustments resulting from the Celgene acquisition of approximately $774 million and $3.5 billion at December 31, 2020 and 2019, respectively, which will be recognized in future periods. Other non-current assets include inventory expected to remain on hand beyond one year in both periods. Certain prior year amounts previously included in provision are presented in utilization. (a) Includes provision for expected credit loss of $12 million in 2020, $12 million in 2019 and $4 million in 2018. Changes to the allowances for expected credit loss, charge-backs and cash discounts were as follows: Non-U.S. receivables sold on a nonrecourse basis were $1.2 billion in 2020, $797 million in 2019 and $756 million in 2018. In the aggregate, receivables from three pharmaceutical wholesalers in the U.S. represented approximately 56% and 50% of total trade receivables at December 31, 2020 and 2019, respectively. December 31, Dollars in Millions 2020 2019 Principal Value $ 48,711  $ 44,335  Adjustments to Principal Value: Fair value of interest rate swap contracts 24  6  Unamortized basis adjustment from swap terminations 149  175  Unamortized bond discounts and issuance costs (303) (280) Unamortized purchase price adjustments of Celgene debt 1,755  1,914  Total $ 50,336  $ 46,150  Current portion of long-term debt 2,000  2,763  Long-term debt 48,336  43,387  Total $ 50,336  $ 46,150  December 31, Dollars in Millions 2020 2019 Trade receivables $ 7,882  $ 6,888  Less charge-backs and cash discounts (645) (391) Less allowance for expected credit loss (18) (21) Net trade receivables 7,219  6,476  Alliance, Royalties, VAT and other 1,282  1,209  Receivables $ 8,501  $ 7,685  Note 10. RECEIVABLES Year Ended December 31, Dollars in Millions 2020 2019 2018 Balance at beginning of year $ 412  $ 278  $ 252  Celgene acquisition —  116  —  Provision 5,839  3,687  2,739  Utilization (5,601) (3,667) (2,707) Other 13  (2) (6) Balance at end of year $ 663  $ 412  $ 278  (a) December 31, Dollars in Millions 2020 2019 Finished goods $ 932  $ 2,227  Work in process 2,015  3,267  Raw and packaging materials 207  172  Total Inventories $ 3,154  $ 5,666  Inventories $ 2,074  $ 4,293  Other non-current assets 1,080  1,373 