[tg] There was only 5/8 as much covid as we thought

[Ken Olum <kdo cosmos phy tufts edu>]

On 1/31/25, Biobot recalibrated the Boston wastewater numbers from
8/29/24 until then, multiplying every number by 5/8.  Assuming it's the
new numbers that are correct, it was apparently not as bad a fall and
winter for Covid as we thought.

                                        Ken