The difference between bitcoins and fiscal currencies is precisely that they are absolutely not subjected with inflation and they are not affected by dollar, euro, yuan and other currencies. But there are fluctuations in its own course. It must be monitored. Bitcoin not depends from the time.
You probably think dollar is inflating because they are printing lots of dollars all the time? That's somehow true, but same affects also bitcoin because more coins are generated by mining. There are just much less new coins.
Ps. Thanks for OP for the graph.
Inflation relates to the monetary base expansion, dollar is the worst of all here because new dollars far exceed growth in the economy. Gold has received more mining then was ever possibly produced prior to the industrial revolution however it still matches population growth globally so is not devalued effectively.
Bitcoin deliberately tries to regulate its mining and rate of production, I actually think the blocks should be produced faster such that technology can secure but its not set that way and so we had previously a problem with a backlog.
The reason dollar is far worse is because its only control is politics, not business or capitalism but the uncontrolled spending by a centralised power. Worse still this currency is used all over the world in economies not related to its origin and is held as world currency. This has allowed great distortion in its value to continue without great feedback. I think its a reasonable assumption that when the standard fails it will have a vast acceleration in inflation and its possible dollar has no worth at all because of loss of confidence.