Fuel Consumption

Today, I realised that my odometer showing the second last bar when I hit 406kms. This means that it will start blinking at 470km. It was the lowest in three months.

Usually, the mileage will go until 440km at the second last bar, and it starts blinking at 490km-500km. Fuel consumption has shrunk by 3okm.
The last time I had this experience was right after I sent this car for servicing. That's strange!
Wondering if I need to send my car for some clinical observation.