If you're in the UK they have to provide you with a copy of all data they hold on you, you may be charged a wee fee for this! And data must be deleted when no longer required, usually three to five years after you last login or delete your account.
If you accidentally deleted your Google Account, you can attempt to restore it by going to our password assistance page within a limited window of time after deletion. Select "I don't know my password," and click the link to verify your identity on the following page.
After this period is when your data is no longer required
If you're in the UK they have to provide you with a copy of all data they hold on you, you may be charged a wee fee for this! And data must be deleted when no longer required, usually three to five years after you last login or delete your account.
Details: Data Protection Act 1998, schedule 1
Information Commissi... What are my rights?
Restoring a Google Account
After this period is when your data is no longer required