On the website, the "Statistics" can be found in the menu at the top of your screen, above the representation of the thermostat by clicking on the last button from the right:
On the application, you can access the "Statistics" from the menu at the bottom of your screen, by clicking on the third icon from the left, representing a curve:
The "Statistics" tab allows you to access your daily, weekly or monthly summaries. On the app, it is necessary to swipe down to access an average of your summary.
The periods on the "Statistics" graph screen are refreshed every 20 minutes (the graph would not be exploitable on shorter times) while on the legend below, it is noted in real time.