Is this about average for how I drive?

[carrotCup]

I filled my Yaris up with 7.985 gallons and drove it to work Friday, then to L.A. and back on Saturday. That put me at 291.4 mi when I filled the tank up again this morning.

Friday was all city driving (only like 20 mi of it), and Saturday was all highway. There were points where traffic caused everything to go really slow, but I'd estimate I went about 75 mph on average on the way up. On the way back, I was sleepy and it was fluctuating constantly between 80~100+ mph. I wasn't really paying attention to the speed.

Now, with all this terrible stop-and-go traffic and obscene speeding and complete disregard for mileage, when I input the info into Fuelly, I somehow managed to pull out 36.5 mpg! So now I'm wondering if that's about normal for how reckless I drive or not.
My '08 hatchback should be getting 35 mi/gallon on the highway, according to FuelEconomy.gov. But wouldn't that be based off of people actually following the speed limit and not being stuck in traffic? I'm in complete awe at how I can drive like a maniac and have my speed constantly fluctuating and still, somehow, get about average gas mileage. I assumed I was getting quite a bit less than that.

So, from everyone else's experience, is it completely normal to drive like an unconcerned jerk and still get fabulous results out of your Yaris? Or is Fuelly just miscalculating my mpg?