“Average” is quite subjective - you don’t consume the same amount each half-hour, so if your consumption is heavily skewed to 4.00pm-7.00pm you will have a much higher average than if, for example, you charge an EV overnight. Your monthly statement has the actual average you’ve achieved. The Average on these graphs is therefore only a guide to what you might achieve if you consumed exactly the same amount of energy every single half hour of the day.