Wow, oil was cheap "back" then, eh? Fascinating to read the price news from that time. I recall worrying about the rising cost of fuel in early 2000, mainly because I had to drive from Portland, OR, to Eureka, CA (about 410 miles) on a routine basis every few weeks... At least my rig got 25 to 30 mpg...

I've kept a complete account of my fuel fill-ups since the mid-1990s. Here's a graph of the price data (sorry about the small text in places on the graph--the embedded summary's not that important, though, for I'm sure everyone knows the details):

Location is primarily northern CA from 1996-early 2000, then Oregon since. Mix in a little WA and ID for good measure.

Looks like I paid $1.15-$1.20/gal or so as recently as early 2003. And that was it. Prices have been climbing since. Definitely volatile, but on a clear upward trend that appears to be accelerating (a hint of exponential growth in price, I think).

The spike in 1999 was supposedly due to a refinery explosion in the SFO Bay Area.

-best

What order of poly did you use to fit your trend line?
2nd order... Just threw that on at the last moment...

-best

Try a third order and see if you get a better fit...
This is America, man...nothing short of a 50th order will do!