I'm posting this only because it took a lot of work to produce, for something else I'm working on about U.S. wildfires
It's an increase of about 5% per year, in real (inflation-adjusted) money.
Is this worrying? I don't know. It probably is if your job is to fight wildfires. Or if you ever have to hope they put out the fire that's heading your way.
Data from National Interagency Fire Center and the FRED economic database.