XML 404 R92.htm IDEA: XBRL DOCUMENT

Exchange rates in US$ (Tables)

12 Months Ended

Dec. 31, 2021

Foreign exchange rates [abstract]

Summary of principal exchange rate used in preparation of financial statements

The principal exchange rates used in the preparation of the 2021 financial statements were:


			Full-year average									Year-end
			2021			2020			2019			2021			2020			2019
Pound sterling			1.38			1.28			1.28			1.35			1.36			1.31
Australian dollar			0.75			0.69			0.70			0.73			0.77			0.70
Canadian dollar			0.80			0.75			0.75			0.78			0.78			0.77
Euro			1.18			1.14			1.12			1.13			1.23			1.12
South African rand			0.068			0.061			0.069			0.063			0.068			0.071