In article , dpb wrote:

Yet again, I conjecture the "normal" readings are estimated and the
large ones are an annual "cactchup" to match reality when the meter is
actually physically read again.

The "level pay plans" that I've heard of and participated in do indeed
have an annual adjustment month, but they don't vary month to month
other than that.

OP did say that a meter reader visits monthly. My guess on the four
identical months is that a meter reading error (of a magnitude
sufficient enough to trigger a red flag) was made, so they used an
average.

HG, to paraphrase John Lennon, "we'd all like to see the bills."