How do you tell is a countries currency is pegged or free-floating? How can you just by looking at it?

I want to know how I am able to tell with only looking at a countries historical currency rates, if I can tell by this is a countries currency is free-floating or pegged to the dollar? How do I tell if I have past years currency in front of me? Thanks!|||There is no way to do so. Currency rate information in publications such as the Wall Street Journal will give a clue; if the current rate is the same as it was a year ago, you may assume that it is pegged. One such pegged currency is the Saudi riyal, which is at 3.75 to the US dollar.