Over the last 979.3 miles... 2,500 miles per quart.

Since I started getting really scientific about it, it seems as though I
may have earlier been mistaken about my car's excessive oil usage.

So far (in miles):
296,919 to 297,919 - 2,500 mi/qt
298,032 to 299,032 - 2,175 mi/qt
299,493 to 300,472 - 2,500 mi/qt

There is some "fudge factor" involved in my measurements, since I'm trying
to quickly measure exactly where the top of the oil is on the dipstick
before it slides down. I go pessimistic, just to be sure.

I've noticed the level is slightly different from one side of the stick to
the other, a consequence of the fact that the stick enters the oil pan on
an angle. I therefore use the same side all the time.