Hello @Fizgil,
Welcome to the EE Community
If you login to the EE website, select Manage> Plans and subscriptions> Manage mobile. Then click See all usage under the part that shows your data allowance, then scroll to the bottom and select Usage history.
That will show you available usage history for your number, though it may not be a full years worth. If you have an android phone the phone will also usually track your monthly data usage with the usage data available in the settings of your phone.
If you do need more history than the one showing in your online account or phone, if you give us a call on 150 one of our guides may be able to access more of your usage history to provide the information to you.
Alex
