Fix drift labels in make_example_batch_data (?)

[tms-bananaquit]

Years 2010 and 2013 technically contain drift relative to the prior years, since they revert to the original distribution. The drift column has those years marked as False, though. This isn't exactly correct.

Making this issue to go back and check against examples and other uses of the method to make sure we don't need to make any fixes other than updating the column values.