Note: On February 6, 2001, we decided to change the definition of
"active user" from a user who has returned at least one result in the
past 14 days to a user who has returned at least one result in the
past 28 days.
This is because version 3.03, which became mandatory on Febrary 1, 2001,
takes significantly longer to process, and result times began falling
beyond the 14-day window.