I may be wrong but my interpretation of this is actually EUR/RUB as shown in the bottom left, so what you’re seeing is the trend of how many rubles to a euro. It used to be 50 or so rubles per euro a year ago, now it’s almost 100 (actually over 100 at time of writing). That means, after accounting for changes in the euros value over the last year, a euro gets you twice as much rubles as it did a year ago, which implies it’s worth half as much as it was (the ruble).