“these BRICS national currencies have declined against the dollar:”
Define “declined” and maybe you’ll have a very scary answer and you won’t post such a thing again.
Five years ago you could trade 69 rubles for 1 dollar. Today it takes you 96 rubles to buy 1 dollar. That is a decline of 38% in purchasing power between the currencies.
ALL of the BRICS national currencies have declined in purchasing power against the US dollar over the last five years. Some more than others, but none have appreciated.
Do you understand what "decline" means in this context now?