Strange, i thought reserve currencies were stored in stable assets that aren't expected to fluctuate much, like the US dollar... Oh i think i see whats next.
I mean, actually yeah that graph does show a pretty stable value. Since 1980 it's gone frome ~$2.50 to $1.00 at a pretty steady rate. For all the financial chaos over that period of time that's a pretty straight line.
While there is inflation, it's been pretty consistently between 2-3% as targeted by the federal reserve, so basically the US dollar is doing what is being communicated, or in other words consistently performing.