City spokeswoman Lauren Passalacqua said a new method of collecting statistics that focused only on the most "meaningful interactions" were partially to blame for the drop.
In Armour, homeowners who paid their sewer taxes in a lump sum sued after the city changed its method for collecting taxes and forgave any amounts owed by people who were paying in installments.
Speaking to Radio 4's PM programme, Tom Steinberg director of Mysociety, said he was drawn to this method of collecting data because HotOrNot style rating systems are "incredibly sophisticated clever ways of doing online polling".